Library builder

■ BY DANIEL S. MORRISON

Adding exterior foam to walls works well for new construction. As long as you meet local wind and earthquake codes, it’s usually pos­sible to build a foam-sheathed wall without structural oriented strand board (OSB) or plywood sheathing. Foam-sheathed walls are braced using one of four methods: • Diagonal 1×4 let-in braces. • Diagonal T-profile steel […]

■ BY MARTIN HOLLADAY R emodelers who open up fiberglass — insulated walls in the middle of the winter are often surprised to see a thin layer of frost on the interior side of the wall sheathing. The frost indicates that warm, humid interior air is leaking through the wall penetrations, leading to condensation on […]

It never ceases to amaze me how many builders omit seam tape from housewrap installations. Although proper lapping is enough to create a watershed, all seams must be sealed to stop air infil­tration. Taping the seams also helps to preserve the housewrap’s integrity throughout construction and makes the membrane less likely to catch the wind […]

Builders have debated the chemical compat­ibility of housewrap for years. Studies have found that certain types of wood siding, like cedar and redwood, leach surfactants (surface-active contaminants) that can affect the water resistance of housewraps. The sur­factants reduce the surface tension of water, easing its ability to pass through micro­scopic openings in the membrane. To […]

When you’re using vinyl siding, which comes with built-in drainage holes and fits on the wall loosely, an ordinary smooth­faced housewrap provides good drainage. But with tightly fastened board siding, any water trapped between the siding and a smooth housewrap will sit and eventually could make its way through the housewrap and into the framing. […]

Fisette conducted independent testing of housewrap not to establish quantifiable data that mimicked real-world performance, but rather to subject the products to a set of sim­ple laboratory conditions to see how they compared. For more on Fisette’s testing, see www. umass. edu/bmatwt/publications. According to Fisette’s research, the best housewraps (those that resist water infiltra­tion and […]

Nowadays, any approved weather-resistive barrier, from #15 felt to high-tech house — wrap, touts the dual benefit of being a weather-resistive drainage plane that also allows the passage of water vapor. But not every product balances these two features equally. To add to this confusion, house — wraps are now available in dozens of variet­ies, […]

■ BY FERNANDO PAGES RUIZ W hen I started building houses nearly 30 years ago, we lapped lightweight #15 asphalt — or rosin-impregnated building paper directly over the stud framing before installing the siding. Nowadays, concerns with energy-efficient construction and moisture infiltration have focused a great deal of attention and no small amount of high-tech […]

In most closed-cell foams, such as those made by Corbond®, an HFC blowing agent is captured in the foam’s cell structure. This gas has a better thermal performance than the air-filled open-cell foam and gives it a higher overall R-value. However, while HFC — blown closed-cell foam might initially have an R-value as high as […]