Split faced block tips

I don’t know about your area, but around here builders went crazy with split faced block for about 10 years.

And the main problem was that they never sealed it.

I have had much business, lately, with water intrusion and condo association inspections for this.

Thought I would share one tip. 2006 3 story plus basement condo building. Brick veneer with limestone trim, at the front, and split faced block (single wythe, which is just plain silly) on sides and rear. Water intusion problems. Typically, the stone coping on the parapet wall (flat roof) was not flashed and that was the major cause of the water.

When I inspected it, I did a MATS test on the masonry. On the south side, I could not pour the water in fast enough. It just seeped into the block. On the north side and rear, the MATS test was satisfactory and it seemed that these walls were sealed. On the roof, I noticed what looked like a varnish on the stone coping and the interior parapet wall, Seemed waxy. Found out that it was linseed oil and many Polish masons use it for sealing stone (old world).

But, here is a stumper. On the picture, you see fairly small (1’ wide x 2 - 3 ’ long) efflorescence patterns on the block. The efflorescence itself was not powdery, like we often see, but was crusty and hard.

I found out, through some trial and error and talking to some old masons, that it was efflorescence. But why only in small spots and why was it so crusty?

Seems like the builder (a year after the fact) applied the linseed oil to the walls and did so with a brush. When I checked what appeared to be the source of the efflorescence, I found that there were small spots (1/2" about in diameter) where the brush missed spots. From those unsealed areas, the water was coming out, with the efflorescence, and was crusty because it had disolved some of the linseed oil.

Also, the usual crap:

  • metal porch attached with lag screws and no flashing above.
  • 1/3rd of the window lintel spaces (between the block and the lintel) was open, 1/3rd was grouted and 1/3rd was caulked. No wonder the water was coming into the top of the windows.
  • 35’ x 95’ flat roof with no vents.
  • 4 Cat 4 furnaces with no combustion air intakes.
  • A/C compressors installed under the porch with only 3’ of above clearance.

Hope this helps;