# How to remove polyurethane sealant from brick mortar?



## Bear4 (Dec 27, 2014)

Hi,

Just bought our first home, it was a foreclosure but in reasonably good shape. The previous owner for some reason applied polyurethane brick mortar sealant around all window openings, please see the photo. I wanted to remove it because in my opinion it looks tacky and does not really serve any purpose, but this stuff is really tuff to remove. I tried using utility knife, wire brush, etc. with no luck. Is there a strong chemical stripper I can use?
Thank you!


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## joecaption (Nov 30, 2011)

That was a DIY that had no clue trying to do a quick tuck pointing job to hide some cracks. I'd be using a 4-1/2 right angle grinder with a concrete blade run down the middle of it, followed up with a flat wire brush in a drill to clean up what's left of the caulking.
Does not matter if you cut into the mortar because it needed to be at least 1/2" deep anyway to tuck point.
Using a mortar bag for applying the new mortar makes for a neater job.


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## rustyjames (Jul 20, 2008)

If that's polyurethane good luck removing it, that stuff has a tenacious bond strength, especially to pourous surfaces.


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## Jmayspaint (May 4, 2013)

Get some shutters maybe. Geeze, I would hate to try to remove that. Joe's solution would work, no fun though. I don't think chem stripping would be effective.


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## Bear4 (Dec 27, 2014)

Shutters is a good idea except for the fact that the sealant is also under the windows as well all the way to the ground (( someone spent days doing this work ...


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## Bear4 (Dec 27, 2014)

joecaption said:


> That was a DIY that had no clue trying to do a quick tuck pointing job to hide some cracks. I'd be using a 4-1/2 right angle grinder with a concrete blade run down the middle of it, followed up with a flat wire brush in a drill to clean up what's left of the caulking.
> Does not matter if you cut into the mortar because it needed to be at least 1/2" deep anyway to tuck point.
> Using a mortar bag for applying the new mortar makes for a neater job.


Well, I attempted this procedure trying to remove some of the sealant, the problem is that the wire brush is starting to damage the brick edges while removing the sealant. From what I was told by the home inspector, the type of brick that I have is called reclaimed brick, actually many of the homes in my neighborhood have the same type of brick, and it is very soft, so it easily gets damaged by the wire brush. Probably would be better to try some strong chemical stripper designed for removal of polyurethane coatings...


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## 1985gt (Jan 8, 2011)

I'd stick with the grinder and a concrete cutting or grinding blade. The wire brush will take the white off the bricks, it looks like paint to me. The caulking was done to cover something up or "fix" it. I'm guessing the mortar is cracking behind it.


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## kwikfishron (Mar 11, 2010)

I bet it was some attempt to fix the real problem... leaking windows.


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## Bear4 (Dec 27, 2014)

kwikfishron said:


> I bet it was some attempt to fix the real problem... leaking windows.


No, I do not believe so, the windows are less than 2 years old, there was actually some warranty paperwork for them we found in the house. These are vinyl impact - rated windows and they are pretty nice, I dont think the windows were leaking...

I managed to remove a small area of the sealant under one of the windows and the mortar appears to be fine with only couple of really small hairline cracks. Looks like it will take forever to remove all of this sealant...


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## kwikfishron (Mar 11, 2010)

Bear4 said:


> No, I do not believe so, the windows are less than 2 years old


I'm sorry you don't believe that. 

It's not the windows I'm questioning, it's the installation.

Think about it. Why would they goop up all of the mortar joints around the windows? 

Looks like Grey Quad to me. I can almost taste it from here.


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## Windows on Wash (Aug 30, 2011)

This will be interesting to see if you can actually get it off.

If it is Quad, that stuff is supremely strong. Your potential saving grace is that it does tend to stay flexible.

The gross over application of caulking does have me worried about the install and flashing of the windows as well.


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## Bob Sanders (Nov 10, 2013)

If you have to do lots of it.... Sandblaster or industrial grade pressure washer.

It would take a while with a sand blaster but you'll have better control. Pressure washer would probably be faster but also a bit more dangerous. If the mortar is weak (which is why people usually throw caulk over it) then an industrial grade washer at 5000 or 6000 psi will start blowing out the mortar.


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## rustyjames (Jul 20, 2008)

Sorry, but sandblasting will kill that brick, and probably bounce off of that caulk.


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## jomama45 (Nov 13, 2008)

It's going to be a slow process by hand, one way or another.

Don't use a power washer or sandblaster, they'll remove the frosting and face off the brick instantly, and the caulk will still be there......


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## Bob Sanders (Nov 10, 2013)

jomama45 said:


> It's going to be a slow process by hand, one way or another.
> 
> Don't use a power washer or sandblaster, they'll remove the frosting and face off the brick instantly, and the caulk will still be there......


You don't need to touch the brick work at all with a pressure washer. The spray is fine enough so that when you hold it close you can get the mortar only. It does take a steady hand though.

If you use a pressure washer properly it will take the caulk off with little issue. You need to cut through and then turn it slightly sideways so the spray attacks the backside of the caulk. It becomes much like a knife skinning an animal.


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## SPS-1 (Oct 21, 2008)

Sandbalasting, powerwashing, or grinding, you are still going to be taking off enough mortar that you will need to be repointing the bricks. Might as well, because, as somebody mentioned, the caulking is not there because somebody thought it looks good. They were covering something -- likely cracked or non bonding mortar. 
Looks like enough of that caulking is on the brick too. 

Is that caulking starting to not look so bad yet?


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## jeffnc (Apr 1, 2011)

I don't think a pressure washer would be a safe choice. Yes, you could aim it inside the brick, and if you're lucky, even inside the brick mold as well, but the problem is that as soon as it takes out some caulk, it's going to start to attack the house wrap and sheathing inside.

A grinder sounds like the most precise way to attack this, though a normal grinding wheel will probably get gummed up immediately. Another option is the attachments you can buy for your recipro saw. For example, the grout remover might work.

http://www.popularmechanics.com/hom...w-accessories-you-should-own-16074749#slide-3


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