A moisture vapor barrier will help keep your home dryer, warmer and healthier – that’s what you want?

A  moisture vapor barrier can prevent as much as 5L of water entering your home every day. Consumer build studies show that as high as 30% of New Zealand homes have moisture issues.  That’s 1 in 3 New Zealand homes that can be making families sick.

The white residue you can sometimes see on floors or walls is Efflorescence, a sure sign of moisture issues.

Signs of moisture in a home

• Crying windows
• Mold on ceilings and walls
• Peeling paint
• Swelling on skirting boards
• Bubbling paint on block or concrete walls
• fine white residue on concrete floors or walls
• Damp musty smell
• Cold and/or wet walls
• Lifting or bubbling vinyl or tiles
• Warped timber floors or dis-colouration at joins
• Damp patches in the floor
• Edges of wallpaper curling and lifting
• Paint on window sills cracking and peeling
• Wet floors

A moisture vapor barrier can help reduce the amount of moisture that gets into your home.

Excessive moisture is a real health concern.  Moisture leads to mold and mold can make you sick.  New Zealand has a damp climate with high humidity most of the year.  And particularly in the colder months, we keep windows and doors closed, this keeps us warmer, but it also prevents moisture escaping.  If you have ever left a load of washing in the machine for more than a day, or a wet towel or clothes in a bag, you know how quickly things can turn nasty. To avoid the negative effects of mold, a home owner needs to control the moisture in their home.

Without a moisture barrier, concrete block walls and concrete floors will absorb moisture from any moisture laden source they contact.  Concrete is like a sponge and will transfer moisture from wet areas to dry via capillary action.  A moisture vapor barrier is a special epoxy coating.  It is important to know that a standard epoxy paint will not act as a vapor or moisture vapor barrier, instead it will peel off the surface of the concrete floor or wall.  Throughout this article you will see me use the terms Vapor barrier and Moisture barrier.  In technical terms there is a slight variation, but the treatment for both is the same.  I repeatedly use both terms for search engine recognition so good people like yourself can find our services.

Waterproofing is not the same as a Moisture Barrier.  Waterproofing stops water from the source side. e.g. you water proof the outside of a wall to stop moisture getting into the wall.  You use a moisture barrier on the inside of the wall when you cannot waterproof the outside.  A moisture barrier will not stop the wall substrate from getting wet, but will stop the moisture getting into the room.  A moisture barrier needs to have an exceptional bond to the substrate to prevent it being pushed off the surface (a waterproofing product is pushed against the surface).

Before having a moisture vapor barrier installed

As with everything that is important, preparation is the key.  The function of the moisture vapor barrier is to have a very strong bond to the substrate (concrete floor or wall) and hold back any pressure that is put on it.  This bond needs to be strong enough to withstand the pressure of the moisture or the moisture vapor trying to escape through  the concrete floor or block wall.  In some instances the moisture barrier needs to hold back a hillside full of water.  you can see why proper surface preparation is required before applying a vapor or moisture barrier.

Professional surface preparation needs to be carried out. This usually involves grind back the surface with diamond grinders to remove any loose or contaminated material and ensure any other coatings or bond breaking elements are removed.  It also provides a rough surface profile that enhances adhesion.

Crack and joint repairs and treatment.

All concrete crack s and floor joint s need to be cut open with a concrete saw blade and repaired with an epoxy or urethane crack repair product.  Major cracks may also need to be stitched for greater repair strength.  We use a select range of very good crack repair products that have proved to be the best of the bunch.  The cracks and joints may also need to be fabric reinforced in the first layer of moisture vapor barrier.

Moisture vapor barrier products we use.

We have 2 main products we use to damp proof concrete floors and walls.

• Creteshield 101 – this is a concrete densifier and works by chemical reaction inside the concrete matrix.  When concrete is laid, it is full of water.  As concrete dries and cures the water escapes and leave capillaries through the concrete. If new moisture finds it way to the concrete it travels through these tunnels.  Creteshield 101 reacts with the lime in the concrete, forms a gel that swells and blocks the pores and prevents moisture transfer, rising damp etc.  Creteshield 101 also hardens the surface of the concrete, prevents dusting and increases the abrasion resistance of the surface.  Unlike other densifiers, Creteshield 101 does not absorb moisture and is permanently fused inside the concrete.  Creteshield 101 does have a limitation – once it has cured (about 6 hours) it is solid and will not move or stretch to address any further cracking of the concrete.  Creteshield is more cost effective, but can not be guaranteed as a moisture vapor barrier.

• Drytek Moisture Vapor Barrier. – Drytek is a 2 component epoxy resin moisture barrier that creates an incredible bond to concrete.  It also soaks into more porous concrete and strengthens the surface.  Drytek MVB will also seal cracks and aid in bonding the slab together.  95% of our moisture barrier work is done with Drytek Moisture Vapour Barrier. Another advantage of the Drytek MVB is that we have a tintable version that can be used as a base coat for our Sparta-Flake and Sparta-Quartz decorative coating systems.