Spalling damage ranges from cosmetic to serious, costly and dangerous. Let the patch sit undisturbed for about an hour, then go over the entire surface with a float or trowel in a circular motion, blending it well with the surrounding surface. Prior to backfilling the foundation on the outside, these voids are typically filled with hydraulic cement. However, these products can fail after a few years if your foundation or retaining wall continues to move slightly, leaving you with little choice but to chip them out and start all over again. Repairing the crack Several masonry patching products, such as hydraulic cement, do an adequate job of filling cracks in concrete walls. The first step to repair cracks in walls made of drywall is to use a utility knife to widen the crack slightly.
Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level. This is enough damage to be considered a structural concern as the pilaster is part of the structure supporting the building above. You pump these products into the joint with a caulking gun; the caulking products remain pliable to allow for ongoing expansion and contraction. Also, cover the entire flange of each injection port with crack sealer, leaving only the extended neck portion showing. This is usually done by injecting an adhesive behind the plaster. If your wall is indoors, fill a bucket with warm water and clean the wall off with a wet washcloth. Field inspection worksheets are included at the back of the volume.
First, scrub the crack clean of any loose concrete, paint or old filler using a wire brush step 1. To create this article, volunteer authors worked to edit and improve it over time. Before you begin repairing the wall, clean it to make sure any cement or mortar you apply will adhere securely. Begin your repair by tapping 3-inch finish nails partially into the crack every 12 inches; these nails will attach injection ports. Following package instructions, mix hydraulic cement with water in a bucket. Did the work cause the fault? To repair a concrete wall you will need an epoxy repair kit.
Trigger disturbances include river erosion, increases in pore-water pressure especially during periods of high rainfall or rapid snowmelt , earthquakes, and human activities such as excavation and construction. If it does, seal it up with crack sealer, too. Gutters are designed to collect rainwater and flow through downspouts directed away from the house foundation. Plug each port before moving to the next. Generally, only older homes are finished with plaster, a gooey substance carefully spread onto closely-spaced, horizontal slatted boards called lathes.
New tenants in the shop next door installed an air conditioner on the roof and set up large advertising boards. This will need to be completely filled with concrete to give you a nice square finished end. However, if the plaster is pulling away from the lath, you first need to shore up the wall with a two-step process that includes a conditioner spray followed by adhesive. Spread mixed epoxy over the crack, extending 1 inch on either side of the crack. The second most common cause is excessive moisture around the foundation. This can be an advantage because it allows time for the epoxy to flow into even the smallest crevices. You'll want to fill so the foam is more or less even with the inside of the block.
The location of the cracks combined with outside observation of backfill level suggests this damage is due to water, frost, and earth pressure. It is no longer a hairline fracture but a more noticeable crack. In masonry block construction, foundation or wall cracks occur more commonly in mortar joints but can also occur across and through the blocks themselves. Structural Damage From Spalling Concrete or Masonry Block At above left the chimnney has been badly damaged by frost: even inspecting from the ground we can see cracks, movement, spalling concrete blocks, and stains indicating that the flue interior is leaking to the chimney exterior. After application, let it dry.
Improper preparation around pipe penetration can cause water intrusion. Wet down the holes with water for best patch adhesion. In instances where there are major structural cracks or when there is evidence of foundation failure as in the image on the far right, we recommend that you consult a civil engineer, not a waterproofing contractor, before deciding on the repair approach to be used to resolve the foundation cracking problem. Make sure the area around the port is covered completely, but don't block the opening. However, if the dampness returns, water is still seeping into the crack and you'll have to wait for it to dry out on its own. Even in the best of conditions, concrete moves a fraction of an inch here or there, not always resulting in a crack.
Mix the compound as per the manufacturer's instructions. But here are some general guidelines: If the crack needs to be structurally repaired and the area needs to be as strong or stronger than the concrete around it, use an epoxy. If the crack goes all the way through the wall, be sure to seal both sides. To fix the crack, you will need to reattach the plaster to the underlying wood slats. Our photo above, discussed at , illustrates severe structural damage to a concrete block foundation wall. National Concrete Masonry Association, 2002. It will begin to form a skin in about 20 to 40 minutes and will harden completely in 1 to 2 hours.