What do you use to seal the side of a brick house to a cemented walkway? I had picked up some polyurethane masonry sealant (Loctite PL S20) but am having second thoughts if this is really what I want since I am dealing with brick and concrete.

 

A decent polyurethane should work to seal the open joint between your brick house and concrete sidewalk. If that is what you are trying to do. Your description of the details is lacking information.

 

Hello, what I am trying to do is seal cracking between the cement & house. Looks like some original type of black sealant is there now. Wasn't sure if the stuff I had could be used on brick since the label only talked about concrete.

 

I'm not familiar with the Loctite product you listed, but if it's like most polyurethanes, it should work against brick as well as concrete. Just make sure the opening is "squeaky-clean", with all of the old joint filler removed. Best to use a tight-fitting, foam backer rod into the opening first, and place the polyurethane on that, keeping it slightly below flush.

 

What is the usual purpose of joining the cement & brick? Is this just a waterproofing move? Does an open gap actually signal some underlying problem or will cause future problems?

 

An unsealed joint allows water to enter the gap and points below it, with a good chance of causing foundation problems. Keeping water out of your basement is always a good idea.

 

Ok, got it - mainly for water as opposed to air/bugs/etc.

In the parts where I see cracks, looks like there may have been a previous attempt to seal this up, as there is a dried up chalky-white appearance around the gap/crack openings. I am just questioning if what I'm doing (sealing with more polyurethane) is a quick fix to a different underlying problem (foundation cracking?).

 

Attached image of what I'm talking about.

 

What you have is someone's attempt to seal the openings (they appear too wide to call them cracks) with an inappropriate material. It looks like remnants of a cementitious product, containing Portland cement, which is too hard and brittle, and lacking elasticity, to remain in the openings as their width fluctuates with changes in temperature. A good polyurethane will remain somewhat pliable for many years, while sticking to the sides of the joint openings.

If you're worried about foundation cracking, take some pictures of them from down in the basement (of the walls and floor where they appear), and then post the pix here. We can make suggestions for options to correct the problems based on the pictures.

 

Unfortunately the basement is finished, so I would have to tear down drywall.

The only information I have is that the cement and the exterior brick have open gaps where sealant was applied. I do not know if there are any foundation cracks; only wondering if the lack of (or failure of) sealant is a sign of foundation cracking or something major.

 

Also, what is the black stuff called? Is this just some black polyurethane? I am not well versed in construction materials, so please excuse my ignorance.

I think this is the point where the structural brick starts on top of the concrete foundation. Why is there only a very thin joint between these surfaces as opposed to a thick mortar bed layer that I see between the bricks?

 

Without seeing it up close (and poking or smelling it), I can only guess that the black stuff is someone's earlier attempt to seal the gap using an asphalt-based sealant of some kind. Or it could also be some top remnants of the house's exterior asphalt foundation sealant, but that isn't too likely judging by the "freshness" of the black color (and the fact that you didn't mention this being a newer home).

Variations in mortar joint thicknesses are not at all uncommon--the concrete below was probably constructed a bit too high, so the bricklayers made up the difference on the starter course by laying it on a "sliver bead" of mortar at that location.

 

This is an old 1950s home. There's the same black stuff on the other side & rear of the house as well (but those sides are lined with grass/soil). Just trying to understand what purpose these materials serve. The black stuff is only at the top of the concrete foundation (can only see about an inch above grade), and the first bed of bricks start on top with a thin layer of mortar.