My face is falling off!

Skier_tom · 06-23-2009, 02:00 PM

Not actually "MY" face, but the face of many of the blocks on my 1940 home. Many of the above grade blocks on the entire perimeter of the home have large portions that are breaking away. The basement interior was finished prior to my purchasing and I don't know how the walls were finished. Last year I attempted a repair on two sides by; 1) Removing all broken pieces. 2) Using a variety of stiff wire brushes and a 1/2 heavy duty drill motor scrubbed down the affected areas. 3) Wet the block and let it soak in, removed puddled water. 4) Filled and finished using Quikrete Fast-set Repair Mortar. 5) Waited 14 days and painted using an exterior grade water base paint. The issue is this spring I already see repair areas breaking away, pealing etc.

glennjanie · 08-15-2009, 04:16 PM

Welcome Skier Tom:
The spalling is most likely caused by water soaking into the blocks and freezing. You may need an epoxy prep to put the repair mortar on. I would not use water and seal it in the wall with paint; rather, paint the walls during the hot, dry summer for better bonding.
Glenn

cre8tivman68 · 10-11-2009, 02:48 PM

Are you sure you used the correct mortar? Many old houses used lime mortar which is softer. It expands and contracts with softer old brick. The Portland cement mortar common today does not give. So, when the bricks expand, they tend to crack and flake. In the 1930s, Portland based mortar and harder bricks became more prevalent, but some people did continue building with the older style bricks and lime mortar for a while. Just a thought.

Also, the whole concept of the lime mortar, in use since Roman times, was that the foundations of buildings constantly expand and contract. It is better that the mortar be softer than the brick and thus bear the brunt of cracking, rather than the brick.