Crown Repair

The last time I had a conversation with a manufacturer rep from someone producing both a "professional" and "hardware store" version of the crown product, he said there were very significant differences, warranties, and such. FWIW.

Masonry chimney? If the old crown has any serious cracks or missing pieces, I'd just remove the crown and rebuild. It's not a huge job. If the cracks are small, then fill with a high bond patching compound and seal. Most masons around here just use Siloxane, which is not inexpensive. Even your new crown would benefit from a sealer, but wait a few weeks after any repair work to do the sealing.

If you do build a new crown, please do not use mortar mix. Use concrete. If in doubt of what to use, pester your local building supply or QuickCrete tech support.

Joful:

Cement is a binder meant to be mixed with sand and/or gravel. Mortar is cement mixed with sand. You would never pour only cement. Why do you say not to use mortar mix to build a crown?

I meant concrete. The brain and fingers don't seem to connect so well when typing on a phone. Mortar mix has the wrong ratio of Portland and sand (and typically no aggregate) for constructing a crown.

For full disclosure, I'm not a mason, but this is what I've read and used myself. I do know some masons will use mortar mix for the crown, but you will find many masons who say this should not be done.

I'll correct my earlier post. Thanks!

My crown also had cracks in it when my friend swept it last summer, he totally rebuilt the whole crown and replaced a brick or two in a very very short time like an hour if that. It was a friend so it was free lol. Well alomost free we pounded a case of beer togrther.

egclassic said:

The crown is in relatively decent shape, but several small cracks here and there. I'd just rather coat the whole thing than fill the cracks.

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Usually, you want to fill the cracks before coating.

I was attracted to this thread (from search) because of the mention of Crown Coat (I'm talking about the stuff with that name, brand name I think), but I didn't see any experience shared here. Did I over look it?

I will not go up on my steep second story roof, so I've had two professionals up there to look as some loose bricks I could see from the ground. The bricks appear to be in the first course under the crown. Both proposed to put on Crown Coat, both said the crown was in "bad" shape. I believe them but should have asked for a photo (hum, maybe one of them showed me a photo/digital picture). They didn't say anything about filling cracks, and one provided me the sales advertisement for Crown Coat, it suggests it can bond the whole crown together. The cost of the Crown coat is in the range of $500, and at least that much to repair the few bricks/mortar in the top course.

From what I have read on this thread it sounds like I should be looking for someone who will take the old crown off and install a new one... no Crown Coat, just a sealer on top. I'll guess this approach will cost hundreds more than using just Crown Coat. I'd put this stuff on myself if I had a more friendly roof to work on.

Speaking of sealers, what's the value of doing a Chimney Saver (brand again) water proof on the whole chimney? I have a three flue masonry chimney, about 28 years old, made with a rather soft looking used brick. The mortar at eye-level looks good to me too. I think this water proofing is just a high profit adder the chimney professionals like to add. It adds about $750 to my cost, chimney is about 10' wide at the bottom, up to about 12 ' then about 6' wide the rest of the way up to a top at about 30'.

A product very similar to Chimney Saver water repellant CURED my leaking chimney. I had a terrible water leak, every time it rained the interior bricks POURED water into the house. I spent YEARS trying to fix flashing, seal the crown, patch mortar joints,perform anti-chimney-leak dances, nothing worked!

It tuned out I had porous bricks. The mortar was fine, but the bricks wicked water right thru. I used a Siloxane based masonry sealer, and for 7 great years I had not a drop of water. I repeated the application and all is well again. The bricks looked kind of soft, evidently they are not a very good exterior grade brick.

Oh yea- this stuff saved my marriage, My wife called herself the "Chimney Widow" because I spent so much time up on the ladder trying to fix it for years.

I guess I'm old school on masonry. What works well has worked well for a thousand years. Excepting the addition of Portland cement 150+ years ago, very few once-new products on the market have stood the test of time.

A leaking chimney is typically the result of bad or failing pointing or fracturing bricks or stones. The fix is typically grind out the joints or cracks, and point. There's no sense in applying a sealer to a wall in need of pointing, as the water will eventually find its way in, and by applying a sealer in an area where there should be pointing, you're setting yourself up for future problems with re-pointing.

There is a separate problem with masonry, of dampness due to moisture penetration of the mortar and brick or stone itself. This can appear to be a "leak" when it condenses in a cool space and runs down the interior of a wall or chimney. This is where sealers are beneficial, ziloxane being the most prevalent.

The last single flue crown I had rebuilt cost under $200. I can imagine paying a few hundred for a multi-flue chimney, but I can't imagine paying $500 to have a sealer slapped atop an otherwise failing crown.

If you're having brickwork repaired, particularly if you have an old house, make sure your mason knows his mortars. Brick is typically more succeptable to using a too-hard mortar than stone. Unfortunately, I hired a (high recommended) mason to do some pointing repair on my ca.1770 house when I was moving in, and too busy moving to give this much attention myself. He used a modern type-S (high Portland) mortar, which is both the wrong color and way too strong for my soft red shale stone walls. I'm still debating what to do about it, as that stuff is damn near impossible to remove, and I'm concerned it will cause my stonework to fracture with seasonal cycling. A good mason knows how to mix his own sand/lime/portland, or at least where to buy the right mix for a given application.

I also looked at Crown Coat last year. And, I also had previously made crack repairs to the crown. Oh, and I also had leaking into my chimney interior; (wet insulation and lightly rusted steel).

When I went up to clean out the crack repairs and try to add a waterproof coating, (not CrownCoat), I found the mortar crown like a moist beach sand. As long as I cleaned it with a wire brush, it crumbled away. I estimate it was 35 years old.

I ended up using a polymer mix from Quikrete to topcoat. (This is sometimes called White Topping in my biz). I then brushed on a masonry waterproofer that is silicone and water based. I mixed the Quikrete with latex.

The whole thing was a major improvement, and last week I checked for leaks and found it dry. I then gave it a new coat of the waterproofing. For good measure I brushed the top few courses of brick too.

I'm pretty happy with it. The crown now looks nice, is rock hard, and feels good.
This might be the stuff:

we use "crown seal" regularly. its great stuff! holds up well, easy to apply
we stock the 5gal buckets, and charge 150 for a crown seal job, parts and labor. Often done during a sweep.
(assuming the roof access is reasonable, if it is super tall we charge more)
our sweeps make notes about crown condition, and i sell the sealer job before we go out to sweep the chimney next year

I used crown coat (bought 1 gallon for $80+/- on ebay) and every 3-4 years I coat the stone with siloxane, havent had a drip of water in the house since, it used to pour water before I discovered siloxane and the crown coat just makes a nice smooth water/weather proof top that you dont have to worry about for years, total cost under $150.