Sealing walls and ceilings in a healthy house

 

The innermost 1/10th of an inch (1 mm) of walls and ceilings is the most important part of a healthy house.  This is what people living in the house breathe in for many hours every day and with the large surfaces it takes very little to become a problem.  This article describes methods for sealing walls and ceilings in both new and existing houses.  The methods can be used on an entire house or just to create a single safe room.

 

Keywords:    healthy house, environmental house, construction, how to, seal, drywall, gypsum plate, moisture barrier, vapor barrier, vapour barrier, membrane, aluminum foil, mold

 

Please note

Please read this entire article before proceeding.  It is especially important to read and understand the warnings about possible mold damage.  The described methods are non-standard and should be used with caution and consideration.  The reader assumes full responsibility for any use of this information.

 

The need for sealing

The most common material used for walls and ceilings in modern housing in North America is drywall.  Drywall is a gypsum plate with a paper backing (usually recycled brown paper) and sometimes contains additives, such as formaldehyde and mold retardants.  The gypsum can come from a mine, or it can be a waste product from a coal fired power plant.  Some gypsum is recycled from demolished buildings.  There can be various contaminants in gypsum.

 

In a new or remodeled house, drywall will need many months to offgas with open windows, before it is tolerable to most people with MCS.  Sometimes it can take years.  Other possible materials, such as manufactured wood panels (plywood, OSB, SIP, etc.), can take much longer.

 

In existing houses, the drywall has often become contaminated by the prior occupants.  Their use of fragrances, pesticides, laundry products, cigarettes, etc. may have been absorbed by the porous gypsum and is then slowly released into the room for many years after.  The drywall could be replaced with new material, but that creates a new problem, though in some cases that is the way to go.

 

There are several ways to attempt to mitigate the situation.  Below is a general list, in the order of approximate effectiveness.

 

      air cleaners (least effective)

      airing out with open windows

      ozoning

      sealing with sealer

      baking out at high heat

      sealing with tile

      sealing with a membrane (most effective)

 

The exact order of effectiveness will depend on the situation, and is controversial, though sealing with an airtight membrane should always be the most effective method.

 

Using air cleaners to clean up a toxic house is probably the least effective method.  The volume of air is simply too small, even with large air cleaners.

 

Having cross-ventilation through the room or house 24 hours a day for months or years is often effective for mildly toxic homes.  This method works even in polluted cities, as long as the outdoor air is less polluted than the inside air.  Some people are concerned about letting in dust or pollen, but those can be vacuumed up afterwards.  A half-hearted attempt at airing out will not be effective.  A constant supply of new outside air is essential.  This method is very time consuming, however.

 

Ozoning may help in some cases, but it must be used with great caution.  If it is done too much, it can permanently make the house smell like ozone.  People have lost their homes doing it too much.  It is better to do it many times for shorter periods—perhaps 10-15 minutes at a time, depending on how powerful the machine is—then airing out for a couple of hours.

 

The ozone should never be inhaled, as it causes lung damage.  It may also convert some chemical fumes into more toxic ones in some cases, possibly making the house worse than before.

 

Ozoning is not effective against formaldehyde and moldy building materials.

 

Ozone is not effective at penetrating cavities and porous materials.  You might find it only helps briefly, until contaminants migrate out to the surface of the drywall again, or simply emanate from cavities.

 

This author greatly cautions against using ozone in most cases.

 

The author does not have experience baking out a house using high heat.  This involves raising the indoor temperature above 100 F (38 C).  The warmer the better.  It may require using many electrical heaters, as the regular heating system rarely can make the house hot enough.  Some people have bypassed the thermostat on electric heaters, or used sauna heaters, to reach high temperatures.  Expect a serious electrical bill.  Some ventilation will be necessary to remove gases released to the air, but too much will lose heat.

 

There are a number of products available to seal a porous surface by applying some sort of sealer that is painted on.  The problem with these products is that they do not provide a fully airtight seal and the product itself can be bothersome to someone with MCS.  There is no sealer that is tolerable to everyone with MCS.  What works for one person may be a disaster to another.  It is essential to do your own testing before using.

 

Sealing with ceramic tiles

Tiles used to cover a contaminated wall in a bedroom.
The ceiling is covered with aluminum foil.

 

Ceramic tiles have been used in several MCS homes to seal odorous walls and ceilings, both in newly built houses and converted older houses.

 

This is a very nice-looking material, but it is also costly.  The grout between the tiles is porous, so odors can still leak through.

 

A few people have tiled over a fully airtight membrane, which is safer than paint and very attractive, but also very costly, as a lathe is needed.

 

See the article Tiling a healthy home or office, for less-toxic grout recipes and other tile information.  It is available on www.eiwellspring.org/saferhousing.html.

 

Sealing with a membrane

In the authors experience, the best and fastest way to seal a surface is to cover it with a truly airtight and benign membrane.  The traditional material used is aluminum foil, while a newer alternative is Tu-Tuff polyethylene plastic.  The rest of this article describes various methods of using these materials.

 

With heavy contamination, it may still be necessary to replace the drywall and then seal it.

 

Warning: possible mold problem

Sealing the walls can possibly cause a mold problem.  There are three types of issues to consider:

 

      condensation in exterior walls

      trapping moisture between two barriers

      trapping moisture from the wallpaper paste

 

Sealing the walls creates a vapor barrier.  Vapor barriers are frequently used in the construction of houses to prevent condensation in exterior walls and sometimes in bathroom walls.  Condensation can lead to mold growth, which is a health hazard.  Moldy houses have been the likely cause of many people getting environmental illness.

 

Vapor barriers can prevent condensation, but they must be placed correctly.  An incorrectly placed barrier can promote condensation.

 

Exterior walls in warm and humid climates

In most climates, the vapor barrier is placed between the drywall and the insulation.  This is similar to the instructions in this article, which puts the membrane (barrier) on the inside of the drywall.  The aluminum or Tu-Tuff membrane becomes the vapor barrier.

 

The problem is that in some climates, the barrier must be placed on the outside of the insulation instead—a very different location.  This is done in some warm and humid climates, such as

 

      Florida

      East Texas

      along the Mexican Gulf coast

      tropical coastal areas

      other warm and humid climates

 

If you live in these or similar climates, make sure to check with local experts before sealing exterior walls.  It should not be a problem with interior walls, as the temperature is the same on both sides (an interior wall is a wall where both sides are inside the house, and not exposed to the outside).

 

In such a climate, the herein described method can promote condensation if done on an exterior wall in houses using air conditioning.  It should be fine on interior walls or if air conditioning is not used.

 

If you live in a climate that has both hot/humid summers and cold winters, the building codes tend to state it is correct to have a vapor barrier on the inside, but it seems to still be a mold hazard during the summer air conditioning season.

 

Double vapor barrier?

If the work is done on an existing house, the exterior walls must be checked to see if there is already a vapor barrier inside the wall.  These can be aluminum foil, asphalt-coated Kraft paper, plywood or plastic.  Some drywall comes with such an aluminum barrier.  Fiberglass insulation often comes with coated paper on one side.  There cannot be two vapor barriers in the same exterior wall, as moisture can be trapped during severe weather.  Some houses have a wind wrap or house wrap that may not be a vapor barrier, but is just an air barrier to slow down wind movement through the wall.  Vapors pass unhindered through these.

 

If the house is found to have an existing barrier, consult with an expert.  It may be possible to perforate the old barrier, or otherwise resolve the issue.

 

Drying the glue

One of the described methods in this document involves attaching a membrane to the wall like wallpaper, using a water-based glue.  The moisture in the glue will be trapped behind the seal and must migrate through the drywall to dry.  This could be a problem in a wet climate, where it is harder for the glue to dry.  This method has only been used in a desert climate.  It is not known to the author if this is a problem or not in a wet climate.

 

Here are some thoughts on ways to speed up drying in a humid climate:

 

      install on a warm and dry day

      use space heaters to promote drying

      ventilate the wall cavity, using a vacuum cleaner or oil-less air compressor

      install only on one side of an interior wall

      install on drywall before the drywall sheet is mounted

 

Aluminum foil

The traditional membrane is aluminum foil.  It can be Heavy Duty aluminum foil, which is sold by most grocery stores, or it can be large, three-foot (1 meter) wide rolls (see vendor list).  The big rolls are heavy and may require two people to handle, but they are faster to use and require fewer seams.  This author recommends using the big rolls where practical.

 

Other types of aluminum products, such as Denny Foil, are too stiff to be used as wallpaper.  The foil in Denny Foil is also very thin and may not provide an adequate seal.

 

There is the unfortunate myth that aluminum foil has a plastic coating on one side, which was supposed to cause one side to be dull.  There is no plastic coating, except for specially marketed Teflon-coated foils.  The dull side is a result of the manufacturing process.  The dull or shiny side can be left exposed as desired from purely aesthetic reasons.

 

Many people choose to leave the aluminum exposed instead of painting it, as this is usually the most tolerable option.  However, it does take some time to get used to shiny walls, and some prefer to paint it.

 

There are long-term health concerns with aluminum.  People with MCS are often advised to avoid direct contact through aluminum cookware and other products.  Whether aluminum walls could be a problem is not known to the author.

 

People who are sensitive to aluminum should consider painting it, which dramatically reduces the aluminum ions in the air.  Or better yet:  use another material.

 

Aluminum foil reflects microwave EMF extremely well.  If it is used on all walls and the ceiling in a room, then it also provides a shielding effect against cell towers and wireless smart meters outside the room.  But radiation from any cell phone, Wi-Fi or other wireless gadget inside the room will bounce around inside the room, and raise the radiation level.  This will happen a lot less if one wall, ceiling or floor is not covered with aluminum (or other metal) or there are large windows without a metal coating (low-E).

 

Tu-Tuff

The Tu-Tuff material is only available from a few vendors in the United States (see list).  It is made of polyethylene plastic, the same kind used in plastic bottles for soft drinks and some brands of bottled water.  It is also used for some types of grocery bags, PEX water pipes and water tanks (with different additives).  It is remarkably tolerable to people with MCS (but test to be sure, as there are people who dont tolerate it).

 

Tu-Tuff comes in rolls.  It is milky-white and semi-transparent.  It is much more durable than aluminum foil, nearly indestructible, and can also be used to cover floors (even carpeted floors).

 

It is more pleasant to look at than shiny aluminum, so there is less reason to paint it.  It is also an alternative for those who are sensitive to aluminum or who prefer a non-metallic material.

 

This author is not aware of anyone who has painted Tu-Tuff.  It is a slick material, so some paints may not adhere well to it.  Test beforehand.

 

Since Tu-Tuff is semi-transparent, the color of the wall will be visible through the plastic, and so will any lines, discolorations, etc.  Overlaps between two pieces of Tu-Tuff will be visible.

 

Sealing walls and ceiling with taped sheets

Bedroom in a Texas home

Mobile home in Arizona

Taping the membrane is mostly used when converting existing houses.  It is the simplest method, and it may allow the membrane to be taken down again when moving.  Since the membrane is not in full contact with the wall, there may be movement of air behind it on a windy day or when doors are opened rapidly.  The membrane may even flap.  This may allow fumes to enter the room, and could produce annoying noise.  It is difficult to seal a ceiling this way, as the membrane will tend to sag (see picture on page 3).

 

If the wall or ceiling is painted with textured paint, or consists of wood paneling or other irregular surfaces, this method may be the only choice.

 

There are two methods:

 

      One sheet covers the entire wall or ceiling

      Strips are taped individually

 

Using one sheet to cover the entire surface can be done by measuring the size needed and taping it together on the floor before raising it.  It will take two or more people to install the sheet.  It is typically installed with aluminum foil taped around the edges.  Thumb tacks could be used for additional support.

 

It is usually easier to tape individual strips of foil or Tu-Tuff across the wall.  Each strip is taped on all four sides.  Then the next strip is rolled out along the first strip and taped on all four edges as well.  This method has less flapping than if using a single sheet for each surface.

 

Some people found it easier to mount horizontal strips across the wall (instead of vertically), starting from the floor and working their way up.

 

It is best to measure out the strip on the floor first, and cut it cleanly with a razor blade or sharp knife.  The aluminum tape may need to be only one inch (2.5 cm) wide.  One person simply cut the tape to size from a two inch wide roll.

 

The aluminum tape may leave marks on the wall when removed sometime in the future.  However, many landlords paint a rented place when a renter leaves.  Perhaps ask in advance what the policy is.

 

The aluminum tape will provide a contrast if using Tu-Tuff.  Thumb tacks can be used instead of aluminum tape, but it will be less airtight and tend to rip the material.

 

Sealing walls and ceilings with airtight wallpaper

Aluminum foil has been used as wallpaper at least since the 1990s.  It was used in Dr. Reas clinic in Dallas and in several MCS houses in Arizona.

 

Using Tu-Tuff as wallpaper has so far only been done in the authors outbuilding. 

 

Attaching a membrane (foil or Tu-Tuff) to surfaces as wallpaper is superior to simply taping it on for many situations.  The benefits are:

 

      it provides a much better seal of the wall

      it is more durable

      it looks better

      there is no flapping

      it can be painted before moving out and the next resident may never notice (unknown if possible for Tu-Tuff)

 

The method described here will mar and wrinkle the surface of the aluminum.  Tu-Tuff is tougher and will wrinkle much less.

 

Surfaces where it may not work:

 

      stucco

      masonry

      textured paint

      wood

      shiny non-porous paint

      vinyl walls (common in mobile homes and RVs)

 

The method has been tested over regular acrylic latex paint, but it may not work over every type of paint.  It did not work on vinyl-covered walls in an RV (the glue did not stick).  Some mobile homes also use vinyl-covered walls.  It will probably work over manufactured wood sheets, such as particle board.

 

Preparing the wall or ceiling

It is necessary to have a smooth even surface to attach the membrane to when wallpapering, just like any wallpaper.  With new drywall installed, joint compound is used to smooth out the cracks between the plates.  The Murco M-100 brand (see list) seems to work well for most people with MCS.  It is basically wheat starch, calcium carbonate and mica.  The joint compound is applied normally over regular paper tape.

 

If Tu-Tuff is used, the areas with joint compound will be visible through the semi-transparent plastic.  This is only a problem if it is not painted later.  In the authors outbuilding, the drywall was simply painted with a thin solution of Murco M-100, after the cracks had been smoothed over, and before the Tu-Tuff was installed.  Three coats made the wall a uniform beige color, which worked well and looks good.

 

Applying aluminum foil as wallpaper

      

 

    

 

The aluminum foil can be purchased in 1 mil (0.001 inch, 0.025 mm) thick rolls that are 3 feet (1 meter) wide.  These came from Alufoil (see vendor list).  For smaller areas, heavy-duty aluminum foil from the grocery store is easier.  Grocery store foil can be used throughout, but it will be a lot more work, and a lot more seams.  It took less than three rolls of these 225-foot (70 meter) rolls to do an entire 830 sq ft (80 m­2) house.

 

It will not work to use foil with a paper backing, or encapsulated paper, such as the Denny foil product.  These are simply too stiff and will not attach well.

 

The foil can be put up with wallpaper wheat paste from the local hardware store, but check that it has no biocides to deter mold.  (In America, check the MSDS.)  It may be possible to use old recipes for glue made out of wheat flour, but that has not been tested.

 

A smoothing tool is needed to smooth out the wrinkles in the foil, and remove excess wheat paste.  It will tend to streak and mar the aluminum foil, but this will not be visible once it is painted.  A special smoothing tool is available from Hyde (see list).

 

Some earlier users of the present system had problems with the foil blistering some months later.  It was found that they had not strictly adhered to the instructions on the packet of the wheat paste.  Aluminum foil is not as forgiving as typical wallpaper.

 

The procedure appears to have been worked out perfectly now.  It includes:

 

      heat up water until almost boiling, before mixing the powder

      soft water appears to work best; add a little salt if using hard water

      mix the exact amount of powder, do not skimp

      if it gets lumpy, add heat or maybe a little water

      apply one coat of wheat paste and let it dry overnight, before a second coat with the wall paper

      apply the second coat of paste to the wall with a roller, then roll the foil over it

      do not let strips of foil overlap; leave a small gap of up to an inch (2.5 cm)

      do not use all the mix in the bucket—throw away the bottom few inches, it will have become diluted with the joint compound from the wall

      make sure to use the smoothing tool to remove excess wheat paste, by pressing it out the sides of the foil

      only do one side of a wall in a day, to limit moisture buildup

 

The strips of foil were put up on the drywall with a small gap, so they did not touch and did not overlap.  When it was dry, the seams were taped using two-inch (5 cm) wide acrylic adhesive aluminum tape from E. L. Foust.  The more common Polyken aluminum tape does not have a strong enough adhesive that will last.

 

The aluminum tape is applied using plastic ice scrapers for car windows.  They make the tape adhere better to the rough surface, when using the dull side of the scraper.  Steel scrapers wont work, while wooden ones probably would.

 

The top and bottom of the drywall is also taped, to make airtight seams against the raw concrete floor and the ceiling.  Then the ceiling is also taped in the same way.

 

The seal will eventually start to leak a little after several years.  By then, the contents of the walls will have largely offgassed.  No seal is perfect.  It is thus still important to use less-toxic materials inside the walls and not fully rely on the seal to keep it at bay forever.

 

Safety grounding of the foil

Consider installing a safety ground for the foiled walls.  In case there is a short between the electrical hot wiring and the foil, the safety ground will trigger the breaker so nobody can receive electric shock.

 

Safety grounding can be installed by connecting the foil to the electrical systems safety ground at electrical outlet boxes.  However, this may be a problem for people who are electrically sensitive, as the house grounding system often carries dirty electricity, which will then be carried on the foil.

 

A better solution is to connect the foil to a separate ground rod, that is not connected to anything else.

 

It is best that there is just one safety grounding path.  With multiple paths (i.e. multiple ground rods, connected separate places) it is possible that small currents may run between the grounding points, which can be a problem for sensitive people.

 

Because of these difficulties, some houses with foiled walls do not use a safety ground for the walls.

 

RF grounding of the foil

Some houses use the foiled walls to shield against outside radio-frequency radiation from cell towers, etc.  When that is the case, the grounding system must be more complicated to be useful.  How to do that correctly is beyond this article.

 

Using foil-backed drywall sheets

Gypsum drywall sheets are available with factory-installed aluminum foil.  These were used in some MCS houses constructed in the 1990s, where they were installed with the foil facing the room.

 

The foil on these drywall sheets is very thin (1/4 mil, 6 micrometers) and this method is now rarely used.

 

Do not fully encapsulate

Do not try to completely encapsulate each piece of drywall.  Someone wrapped a sheet of drywall completely in foil, including the sides and ends.  The moisture from the wheat paste was trapped inside, with the result that the foil corroded.  Mold will also eventually grow where moisture is trapped.

 

Applying Tu-Tuff as wallpaper

    

 

 

Cutting bubbles on the edge of the sheet.

 

The Tu-Tuff was purchased in a four-foot (1.3 m) wide roll from the manufacturer (see vendor list).  It is available in wider rolls, but they have seams and are also too big to handle.

 

The plastic was glued to the wall and ceiling using a wallpaper paste from the local hardware store.  Some wallpaper pastes contain biocides — check contents before using it.

 

It is essential to strictly adhere to the instructions for mixing the wheat paste, and be sure to use hot water.  Otherwise the wheat paste will not have its full strength and may come loose later.

 

A special smoothing tool was used to smooth out the wrinkles and remove excess wheat paste.  This tool is very cheap and a tremendous help.  It is available by mail order from Hyde (see list).

 

It is easier to install Tu-Tuff than aluminum foil, as it is a little stiffer.  It will also wrinkle much less.

 

The steps are:

 

      Heat up water until almost boiling, before mixing the wheat paste.

      Soft water may be best, a little salt can be added if using hard water.

      The exact amounts of wheat paste must be mixed according to instructions.

      The paste is applied to the wall using a roller and allowed to fully dry.

      A second coat of wheat paste is later applied over the first coat.

      Pre-cut the Tu-Tuff pieces before mounting them.  A T-square helps in making the ends be cut straight.

      Roll the Tu-Tuff out over the wet wheat paste.  Use the smoothing tools to remove excess paste, and make it as smooth as possible.

      The unavoidable small kinks at the edges can be cut with a sharp knife or razor blade.

      Adjacent sheets should overlap a couple of inches (about 10 cm).

      The ceiling pieces should be installed first, and made a little too long so both ends go down the walls a few inches.  This creates a smooth transition.

      Do not use all the mix in the bucket.  Throw out the bottom few inches as it will have become diluted with joint compound from the wall.

      Only do one side of a wall in the same day, to limit moisture build-up inside the wall.

 

Overlaps between sheets will be visible through the transparent material, so it is important to make the cuts straight and even.  It is very difficult to correct once the sheet has been mounted.

 

Sealing electrical outlets

The edges of the walls and around wall boxes are sealed with aluminum tape.
The steel mesh is for trim and baseboard tiles.

 

The electrical outlets provide a path for the air to move through the wall.  This air movement happens when there is wind outside the house, but may also happen when doors are being closed or exhaust fans run, etc.  The air will pass through the wall cavity, where it may become contaminated.

 

In new houses, and very contaminated older houses, the wall cavities will be contaminated.  There are insulation, wooden studs and the back side of the drywall.  These may all have absorbed contamination in an old house, and simply are new in a new house.

 

In lightly contaminated houses that are older than at least ten years, the inside of the walls may have offgassed enough that there is no need to seal the outlets.

 

The ventilation through the outlets may be beneficial to prevent moisture buildup and mold growth inside the wall.  See the section discussing the vapor barrier issue.

 

There are a few ways to seal the outlets.  The most obvious one — taping over the slits — is not enough.

 

The simplest way is to unscrew the face plate and cover the entire hole with Tu-Tuff, or other plastic.  Aluminum could cause a short and should not be used.  It should be firmly taped all the way around to make an air tight seal.  Then put the face plate back on again.  This may not look so nice, and the outlet is no longer usable.

 

There are plastic gaskets sold in hardware stores, which can cut down on air movement.  But even if the slits are also taped, it may not be tight enough.

 

A more thorough method is to caulk each wall box fully.  Make sure to use the material that is tolerated the best.  Sprayed foam in a can (such as the polyurethane foam in the Great stuff brand) works very well.  Caulk can be used also, but may not seal as thoroughly.  There is no brand of caulk which is the best, i.e., tolerated by everyone with MCS.  And they all need to be offgassed for a significant amount of time, so be careful.

 

In a new house, the wall boxes are sealed after the wires have been pulled, but before the drywall is put up.

 

In an existing house, the outlets must be unscrewed and pulled out of the wall box, to be able to reach all the holes in the wall box.

 

The sides of the box should also be taped to the edges, so there is a tight seal around the box.  If using Tu-Tuff wallpaper, the aluminum tape can be covered with small strips of Tu-Tuff, attached using the wheat paste.

 

Sealed wall box in a new house.

 

      

Wall box sealed with aluminum tape (left), then covered with Tu-Tuff strips.
 (glued with wheat paste)

 

Baseboards

Aluminum baseboard taped to the floor and wall

 

 

tiled baseboard and door trim

 

This section may only be of interest for new construction.

 

The baseboard serves a number of functions:

 

      protect the wall against damage from footwear, vacuum cleaners, etc.

      seal the crack between wall and floor

      it looks good

 

To complete the seal of the wall, aluminum tape can be used to seal the wall to the floor.  This is best done before installing the baseboard.

 

The baseboard can be made of tiles that are cut in four inch (10 cm) wide pieces and mounted with thin-set mortar over steel mesh.

 

A much simpler method is to tape a piece of aluminum drip edge flashing (L–shaped profile) to the floor and the wall.  This is not as durable, however.

 

Windows

AppleMark
Tu-Tuff window sill


Tiled window sill

 

The window sill and frame can be covered with Tu-Tuff, aluminum foil or tile, if needed.  This is probably not necessary in houses with rather thin walls.

 

Some people simply have loose pieces of cut floor tiles in the window sill, to protect the aluminum foil or Tu-Tuff.

 

Tile set with thinset is best to catch condensation, which can cause mold problems if making the drywall wet.  Make sure to protect the ends of the window sill against condensation, too.

 

To paint or not to paint

House in Arizona with bare aluminum walls.  The people living there have hung
cotton drapes on their walls.

 

It is a big decision whether to paint or not.  Shiny aluminum walls do take some time to get used to, while painted walls are nicer and give more of a sense of normalcy.  Many people do live with bare aluminum walls and dont really think about them much after awhile.  They do get less shiny after some years.  Some people have hung drapes over them.

 

The walls can be painted later, if the house is sold to people who do not have MCS.

 

Preparing for painting

If using aluminum foil, the walls should be washed to remove oxidation so the paint will adhere better.  The Red Devil TSP product (which no longer contains any phosphate) works well and is very tolerable.  Other cleaners may work fine, too.  Some people have omitted this cleaning entirely, and the paint still adhered well.

 

A putty can be made to spackle around the taped seams, to smooth them out so they do not show through the paint.  This is very similar to when applying joint compound to drywall, and the same Murco M-100 product works well here too.

 

If using Tu-Tuff, and you wish to paint it, you are treading on new territory.  This author is not aware of anyone who has done that.

 

Choosing a paint

Painting the interior is problematic and should be very carefully considered.  Even a small house of 850 sq ft (88 m2) will have about 2500 sq ft (260 m2) of walls and ceilings to be painted.  That is a lot of surface covered with a potentially bothersome substance.  There are a number of paints available that are specially designed for sensitive people, but no paint is universally tolerated by everyone with MCS.  If you choose to paint, expect to add months of time until the house or the room can be used.  And that is best-case scenario.  Several houses have been ruined by painting them.

 

It is not just simply choosing a low-VOC or no-VOC paint (and no-VOC paints may still contain VOCs anyway).  The paint will still need to be suspended in something, which then evaporates while the paint cures.  A high-VOC paint may possibly be very tolerable once it has fully cured.

 

Do not make the common mistake of choosing a paint on the recommendation of others.  There is no substitute for testing it yourself.

 

House with aluminum foil walls after it was painted.

 

The best test is to spend time in a newly built house, using the same paint and other materials you intend to use.  And even that is not perfect.  If the house is not tolerable, then the question is why.  There are likely many reasons, and it is difficult to know for sure.

 

A more common test is to buy a sheet of drywall.  Enclose it totally in aluminum foil or Tu-Tuff, including the sides and ends.  It should be taped together — do not use wheat paste, as the moisture will be trapped.  Then paint it, and let it offgas for at least a month.  Then see how you do with it.  The final test is to sleep with it next to the bed.  Of course, if you sleep outside or dont have a safe place to sleep, that wont be possible.

 

Some of the current paints worth looking at include

 

      Benjamin Moore

      Bioshield (Kinderpaint or their solvent-free wall paint)

      Sherwin Williams (Harmony)

      Best Paint

      Murco M-100

      AFM

 

The above list is in no particular order, and is not a recommendation by the author.  Make sure to follow all instructions judiciously.  Some paints wont cure if each layer is not allowed to cure for a few days before the next is applied.

 

For more information

Other articles about less-toxic building methods can be found at www.eiwellspring.org/saferhousing.html.

 

 

Acknowledgements

The details of using aluminum foil as wallpaper were developed by Bruce McCreary.

 

Lenny Dikes has built several MCS houses, and also contributed to the development of these methods.

 

Disclaimer

The methods described in this document are considered experimental.  They are not established methods as they have not been used on a large scale and by people with no prior experience in MCS housing.  Most of the methods have only been used in a desert climate and may not be suitable for other climates.  The reader is expected to apply common sense and seek out expertise where needed, and is ultimately responsible for the result.  This document can only be considered a guide of what works for some people.  Neither the author, Bruce McCreary nor Lenny Dikes can be held liable or responsible for any outcome.

 

Vendor list

Alufoil (0.001 soft alu foil in 3 ft wide rolls – part no. 210SR36X225AL)

631-231-4141

www.alufoil.com

 

Hyde (wallpaper tools, SKU 45808)

1-800-872-4933

 

Murco (M-100 joint compound)

1-800-446-7124

www.murcowall.com

 

Sto-Cote (Tu-Tuff in 4 ft wide rolls)

1-888-786-2683 / 262-279-6000

 

Red Devil (Red Devil TSP cleaner)

1-800-4ADEVIL

www.reddevil.com

2010 (updated 2015)