Thorocoat Yes or No?
We had a peeling stucco layer on our back brick wall and some eroded pointing. The price for re-pointing are very high, so we are considering a bid to repair and recoat. The estimate says they are using a product called “Thorocoat.” I’ve read previous threads about the potential dangers of Thoroseal… and an architect…
We had a peeling stucco layer on our back brick wall and some eroded pointing. The price for re-pointing are very high, so we are considering a bid to repair and recoat. The estimate says they are using a product called “Thorocoat.” I’ve read previous threads about the potential dangers of Thoroseal… and an architect friend once explained to me (persuasively) that you should NOT seal brick walls.
Is Thorocoat ok by this measure?
Are there reasons to NOT use?
When we priced repointing it was $20,000+ and this job will be $7,700 including repainting the fire escape.
If I learn it’s a real error to recoat, maybe we’ll consider a loan for repointing.
thanks all previous replies a huge help in our process.
If the bricks are sound, Don’t coat them with anything, just repoint. If there is signigicant spalling, the cheapest, although far from ideal solution would be to re-stucco them. You can paint bricks, as long as it’s with something that is not going to trap water. I’ve seen many, many chimneys ruined because people smeared tar up the sides and ended up with exactly the condition that Brooklyn Butler talks about. Thorocoat is made to breathe so you could conceivably go that route. Thoroseal waterproofs, so any existing moisture in the bricks would be trapped. Make sure the contractor doesn’t mix them up. The first step you need to take is to find out exactly what shape the bricks are in, that should drive what you end up doing.
butler: Almost every house on my block is sealed in the back. None of them seem to be experiencing any failures, and all seem to be several years to decades old.
If you need to repoint you can’t get around it by coating the surface of the facade. repointing deals with the mortar joints, coating deals with the brick surface.
If your mortar joints are open and crumbling you will need to re-point, no shortcut is recommended.
Now, if after you repoint you find that the bricks themselves are spongy and porous, you can apply thorocoat, which is a breathable, or vapor-permeable, paint. If your bricks are good there would be no reason to apply the coating.
repointing is expensive because it is tedious and long work (when done properly). It is the project that most home owners in our region get wrong, most likely because they think it is a “no-brainer” when in reality it is a very delicate and technically exacting job. An architect or owner’s rep can help you make sure that the contractors use the proper mortar and do the job neatly and well. There are so many ways to ruin a wall through bad repointing. Examples are everywhere you look in Brooklyn.
Actually the consensus appears to be that brick can be painted (several home improvement sites), so I think the “don’t paint” is an old wives tale. Or maybe an old fuddy-duddy’s tale, given the antipathy to colorizing your exterior.
I think I will look into a SF style painted lady style for my house now, before it gets lanmarked.
The downside does seem to be maintenance…forever.
No, no, no! Bricks need to expel water, and your historic brick wall was constructed with the idea that moisture from the inside will be able to navigate through the entire (multi-wythe, or multi-layer) thickness to the outside. If you stop that progression you’ll trap that water between the brick and the Thorocoat. After a few years of freeze-thaw the bricks will spall (the outer, fired, surface will pop off) behind the Thorocoat. Eventually the Thorocoat will come off, and you’ve got a bigger problem than you had before–mainly that you’ve got an unfired (i.e. soft, fragile) brick surface exposed to the elements. Your only solution at this point is brick replacement.
I also wonder if by trapping that moisture inside your house if there’s a potential for a mold problem, too. I haven’t heard of that happening specifically with Thorocoat, but I have heard of it happening with poorly installed vapor barriers.
I suppose that you could do Thorocoat, if you also installed a vapor barrier on the interior wall surfaces, and increased the ventilation inside your house so that the moisture had somewhere else to go other than the walls. Then, of course, you’re looking at a very complicated project and a lot more than $7,000.
The guy who’s selling you the Thorocoat product is not going to tell you any of this. He might even tell you that Thorocoat is vapor permeable. If so, ask this guy for the data: the rate at which moisture can get through that coating. It should be at least as permeable, if not more, as your three-whythe brick wall. Is this guy telling you that you can paint the Thorocoat in a few years–when it starts looking dirty? If so, that will GREATLY affect the permeability of that wall surface.
It probably isn’t. Your architect friend was right. It’s bad idea to coat undamaged, sound bricks with anything. You might as well put vinyl siding on this wall.
$20,000 is a lot for repointing one elevation in this economy. Shop around. Also, you’ll want to use a soft mortar (usually Type N, but there’s a lot of debate as to whether or not Type N is actually too hard). Using a mortar that’s too hard also creates problems, but that’s a topic for another thread.
I have definitely heard that bricks need to breathe with the changing conditions (ie, expand and contract) and would recommend the repointing route. But that quote does sound very excessive.
Repointing and thoroseal/thorocoat are entirely separate issues. You’ll need to remove any stucco or thorocoat to fully expose the current condition of your bricks and mortar. Stucco and thorocoat are often applied by sellers to disguise an existing need for repointing. If you allow the mortar to continue to deteriorate, at some point you’ll be dealing with much greater and more expensive structural issues, as well as with damage from water penetration. Lots of technical notes from the Brick Industry Association at this site: http://bit.ly/cgtnDK
More information in this NPS Preservation Brief: http://bit.ly/bY14m3
Try VinRoy for pointing:
646 554 4513
516 623 5867
718 735 6725
call my mason Shahab 646-523-7155…get estimate from him.
Has done lot of work for me over the years.