Welcome to my Homepage Blog. Here you'll find stories about inspections I have done and facts I think are interesting to share with you. Come back often to see what's new.
-Glenn, a.k.a. The House Whisperer
| Don’t Miss A Step |
| Written by Glenn Stewart |
| Friday, 11 November 2011 04:28 |
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Home inspectors see cracks in concrete surfaces at nearly every home inspection. This backyard concrete patio developed a large crack within a few years of installation. What happened? Cracks of this size are typically caused by a combination of things:
Expansive soils contain a lot of adobe/clay and swell when wet... Not good for a concrete patio poured directly on the ground.... A bed of gravel or sand helps 'float' the concrete above the expansive soil. If there's expansive soil and the gutter downspout discharges water onto the patio... the water usually finds its way under the concrete patio... swells the soil and lifts the patio... cracking it. Rebar steel or steel mesh is used in patios to give it strength and to hold the concrete together... If reinforcing steel or mesh isn't used in the patio... water or a tree roots can find their way under the patio... put pressure on the concrete slab and crack it. Leaving out a step when building a patio can lead to cracks: No gravel bed... No steel mesh... Not enough concrete thickness... No control joints in surface... Weak concrete mix... No patio slope... And don't plant the Redwood tree next to the patio. |
