Archive for January, 2016

Cavity Wall Insulation Problems: Is Your House Rotting From Within?

Cavity Wall Insulation Problems: Is Your House Rotting From Within?

Common Cavity Wall Insulation Question: What are Masonry Veneers and Cavity Walls?

A masonry veneer, stone and brick, for example, is a non-structural finish that’s installed on the outside of an exterior wall for its aesthetic qualities and as its weathering surface. A cavity wall is a common type of exterior wall construction, an assembly consisting of an exterior, non-structural veneer, a structural inner wall, wood frame, for example, and a cavity, which is an air space separating the two. The purpose of this separation is to inhibit rainwater that penetrates the masonry veneer from reaching the structural, wood-frame wall and to allow for its proper drainage. Why is this important for projects in Connecticut or New York?

Cavity Wall Insulation Problems: The Problem? No Cavity

All too typically in Connecticut and New York, a masonry veneer is installed without a cavity, that is, tight to the wood framing with only a building wrap, building (tar) paper or Tyvek, for example, separating the two. Why is this a problem? Masonry is porous; it absorbs and allows water to pass through it. Once this happens – and it will happen – that water needs a place to go. If the veneer is installed without a cavity, it will reach the wood framing, causing rot and promoting mold growth. Also, New York and Connecticut winters frequently have above-freezing temperatures during the day and below-freezing temperatures at night. Any rainwater that penetrates and remains captured within the masonry veneer has the potential of freezing – water expands when it freezes – thereby causing freeze-thaw damage to both the masonry and the wood framing.

By contrast, if the masonry veneer is installed with a cavity, rainwater that penetrates to its inside surface has the ability to flow by gravity down to the bottom of the wall where it can be directed to the exterior thereby preventing damage associated with walls built without a cavity.

Assistance with Your New York and Connecticut Project
The Beacon Projects Group can both advise you whether the masonry veneer you are planning to install has been properly specified and detailed and assist you with your contractor to assure its proper installation.


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