Concrete Materials and Admixtures

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Best Mix for Pumped Concrete

Plans for an infill project call for a poured stem-wall foundation, but the urban site has limited access for a regular concrete truck. A pumper truck would be ideal, but I'm concerned that the pumped mix won't provide the required 4,000-psi concrete. Is this a legitimate concern? More

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ZipWall ZP4 Dust-Containment Kit

Create a temporary dust-containment wall or 'room' with plastic sheeting using the... More

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Clips for flat tiles; mounting blocks; aluminum-and-glass railing; crawlspace ventilation; fibercement siding panels; more More

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Mudsills and Out-of-Level Foundations

Recently we contracted to do a house with precast foundation walls that were set out of level - up to 3/4 inch over 30 feet, in some places. What's the best way to shim and air-seal the mudsill? More

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In the News

Chinese drywall investigated in Florida; West Virginia builder sued for installing fake radon systems; green building stats fall short; more More

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Removing Kerdi Epoxy Grout With Heat

Q: Using a heat gun is an approved method for removing cured epoxy grout from tiles and fixtures [see Q&A, 5/08]. But can the same technique be used when the tile has been installed over Schluter’s Kerdi waterproofing membrane, or would the heat damage the membrane? More

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Is It Safe to Retrofit Exterior Foam Insulation?

Q: I built a lot of homes in upstate New York in the 1980s using 2x6 studs, fiberglass batts, and a poly vapor retarder for the shell. Given the rising cost of heating and cooling, the owners are asking about energy upgrades to their walls. I'd like to suggest adding 1 or 2 inches of rigid foam on top of the existing OSB or plywood sheathing, followed by new siding. Would the presence of polyethylene vapor retarders make this a risky retrofit strategy? More

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Vapor retarders in North Carolina; cost of curved coffered ceiling; hiring illegal immigrants More

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A Pier-and-Beam Foundation For a Coastal Site

Where unstable soil and periodic tidal flooding are a concern, helical piers... More

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