Concrete Spalling Behind Siding

Concrete spalling typically begins when the steel reinforcing embedded within the concrete member rusts.

Concrete spalling behind siding.

Spalling of concrete affects a broad variety of structures including framed buildings multi storey car parks bridges jetties tanks and bunds. Mix one part type 1 portland cement and one part fine sand by volume. While spalling can occur on concrete it s especially a concern on stone brick or block where portions of the assembly can degrade to a point where they crumble. James hardie recommends that a slip sheet joint flashing is installed behind each butt joint in the siding.

Without both of these elements the steel bar does not rust. The wood that goes under residential siding exterior sheathing performs several functions. Spalling is break away of concrete surface which often extends to the top layers of reinforcing steel. The siding on this gothic revival style home looks like wood clapboard but it s actually fiber cement painted a custom color.

It adds insulation waterproofing and structural support for the framing. Spalls can appear because the rebar has been exposed and humidity and water have begun to rust the rebar or because the concrete joints were improperly built. 7 inch wide smooth lap siding primed about 1 50 per square foot picking the right siding for your house is a delicate balancing act between good looks durability maintenance and affordability. Contractors might make the mistake of adding too much water but frankly most don t make mixing errors.

As weather changes the concrete expands causing it to spall which leads to further deterioration. Spalling also can be caused by freeze thaw cycles in concrete and masonry products that have a high moisture content. Rusting of the embedded steel reinforcing occurs when that reinforcing bar is exposed to water and air. Before that dries mix three parts fine sand and one part portland cement in your wheelbarrow with enough water to make the mix the consistency of thick oatmeal.

Spalling that occurs in a concrete driveway or sidewalk typically happens because the weather changed during the hardening process or something else occurred to prevent the concrete from finishing its curing. Add water until the mixture is the consistency of thick paint then brush it on the damp concrete. This is a 6 wide piece of weather resistive material to make sure that no water gets through. Hydrostatic pressure is not the only cause of spalling.

It also provides a. Contrary to popular belief concrete is porous.