We had brick veneer put on our home about two years ago and were told we would never have a water problem again  Well, we are now having an addition put onto our home and I’m finding things probably weren’t done right with the brick.  I don’t remember the mason using brick ties.  I remember asking him about support and he said the mortar that dropped behind the brick gave it support – I think it was because it stuck to the house.  Also, I don’t think we have Tyvek water-proofing paper on our home except for around the windows/doors.  I don’t remember the mason adding this.  He did leave a 1 to 2” gap between the brick and the wall, but I’m still nervous about what I’m hearing.  I actually stuck a brick in a couple inches of water to see how it would penetrate the brick and it never seemed to go through completely, although the brick might have been damp, but can’t see that damaging the wood to our home with such a gap.  We paid about $15K for this job and we are reluctant to take it down.  The damage this could do would cost a fortune to repair.  We love the brick, but don’t want future problems.  How do I know if we need to do something about this?  We don’t see any water coming into our home…yet.-Lisa , New Hampshire 

            Unfortunately brick veneer, as it is commonly installed, is at high risk for water getting into walls and causing mold infestation and structural damage.  Houses built in the open are at particular risk during wind-driven rains.  In the Midwest such rains typically hit the south and west sides of the house.

            Brick veneer is an attractive building cladding that certainly both costs more and increases the value of a house.  It may be applied to the front of a house as an accent, cover lower levels, or completely cover the exterior of the house.

            Both brick and mortar absorb water relatively easily.  This water can then wick inward toward wall cavities.  This wicking can be enhanced by a variety of factors including sun shining on brick veneer surfaces after a rain.

            In addition to wicking, water can readily move through the small crevices common in poorly-applied mortar as well as through settling cracks.  Such movement through crevices in mortar and settling cracks can result in a significant amount of water in wall cavities.

            Model building codes recognize this issue by recommending good masonry construction practices.  These include the placement of weep holes at the base of the mortar approximately 24” apart, a ¾ to 1″ free and clear gap between the brick veneer and the adjacent wall and a water repellant cover over the interior wall.

            Water intrusion through brick veneer is facilitated by the excess mortar that joins the brick with structural building material such as oriented-strand board.  The passage of water into the cavity is inhibited by building wrap materials such as Tyvek , as well as, building felt.  Tyvek sheds water and prevents rain water from entering walls directly.  It does, however, apparently allow the passage of water vapor inwards which has the potential for subsequently condensing in the walls.

            When Tyvek is not present, water damage/staining may quickly show up on lower wall surfaces such as those at floor level.  Carpets may become wet with tack strips and tacks stained/corroded.

            The good thing about the absence of Tyvek is that water intrusion and mold infestation problems become readily evident so that homeowners know they have a problem.  When such building wrap is present, water intrusion into wall cavities is less likely to occur (though in some cases mold infestation of building cavities has in fact occurred).I am familiar with cases wherein brick veneer was removed and replaced according to code and good practice procedures and yet water intrusion/mold infestation problems re-occurred.

April 15, 2004

 

Indoor Environmental Quality (2000), Thad Godish Ph.D., C.I.H

Direct E-mail 00tjgodish@bsu.edu