How To Seal A Concrete Block Wall
Step 4 paint on two coats of concrete block sealer to the interior of the block.
How to seal a concrete block wall. Patch any holes in the basement cinder block wall with your hydraulic cement. The cement becomes hard quickly so be time efficient. Push the cement into the cracks and crevices making sure to pack and seal. Garage walls are a perfect example of this.
Standard concrete block is semi permeable 5 perms. Preventing resultant creation of acidic conditions in the concrete which in turn will cause rusting of all steel reinforcement. This sealer will penetrate the block pours sealing them off. A cinder block is much more porous compared to a standard concrete block or poured concrete.
Why cinder block walls leak. Concrete blocks commonly begin to show signs of dampness or worse leak water soon after exterior waterproofing. Allow the cement to dry before proceeding usually 24 hours. Heavyweight concrete blocks are semi permeable 5 perms and less so when the hollow cores are filled and packed with a slurry mix of concrete about 2 perms.
How to seal corners and slab penetrations. Some tests show 4 8 perms for hollow concrete blocks and 2 4 perms when the blocks are filled with a slurry mix of concrete. Distribute the tar evenly across the wall leaving no more than a 1 16 inch thick coat. It can also develop small pinhole openings that act as capillaries for water transmission.
Steel expands up to eight times its original size and eventual destruction of your re enforced concrete or masonry block walls. Water moves easily through porous concrete so sealing interior walls is necessary to prevent moisture from seeping in promoting mold growth and that cold damp basement feel. Cinder blocks are classified as permeable to water and water vapor 10 perms. If the conditions outdoors are cool allow the bucket contents to sit in the sun for an hour to loosen the contents.
Concrete is a porous material when fully cured. Use a masonry sealer such as thoroseal that also patches cracks 35 for a 50 pound bag. Block foundation walls will provide only a weak barrier against capillary water seepage and water vapor. Seal the entire concrete wall with a waterproof masonry.
The best and easiest way to make sure your cinder blocks will not leak is to take preventive actions before you need it.