Brickwork/chimney top: care and repair?

Here's some pictures of the bricks / top of my chimney. Any thoughts on what i should be doing and are these a problem? This is the only brickwork on my house.

The moss? brush it off?
The holes / cracks / crumbling in the mortar
The cracks and moss on the concrete top of the chimney
Anything else you see as red flags?

The house was built 43 years ago and we've owned it for 20 years. In the last 20 years, we haven't done anything to the brick / mortar / chimney. Is there general care that should be done? I did spray Costco's Wet and Forget on the moss / bricks / mortar recently. At some point should I brush off the moss?

Does this belong here or in the chimney forum : ) ???

Thanks!

 

I would probably wire brush and acid wash the moss off, rinse, paint on some bonding agent onto the cap, resurface the cap with a thin layer of concrete repair / patch mix. Holes in mortar joints can also be patched, but if any mortar joints are cracked really bad, you should grind them out a little before tuck pointing them.

Once the cap repairs have cured, caulk the perimeter of the tile flue with a polyurethane sealant meant for concrete.

 

I just redid my chimney during the past summer.
I didn't patch the cracked crown cement. I removed and replaced it.

 

If the cap is separating from the bricks that it sits on, that's a good time to replace it. If the edge where it meets the brick is still bonded, or is just a hairline, it's probably best to patch/resurface it.

The giant crack in the first pic looks like it has been there for a while. Concrete is going to crack, especially an unusual shape...

If you decide to repair it, that big crack should be filled first with the same sealant you use around the tile flue, because it's now an expansion joint.

 

Maybe not right now, don't know what the weather there is, but I would plan to replace the crown this year. On the other hand, it looks like, with the previous advice, you should still have some usable years left in it. Looking at the outside edges of it though, there is plenty of opportunity for water to work its way under, where it will them get into the bricks, most likely eventually freezing, and causing the outside of the bricks to break away. If you do go this route, I would make the new crown at least 1" thick at the outer edges, assuming you can still get slope away from the flue, and form it so as to provide a minimum 1" but preferably more like 2" or so of overhang, so that water will drip away from the face of the bricks. Where the crown is against the flue, I would wrap the flue with something pliable, sill seal works pretty well for this, because the concrete will shrink as it cures, possibly causing premature cracks at the corners. Then, once the concrete has set, you can slice the sill seal or whatever you use flush with the new crown, and caulk the gap.

 

That is a mortar crown, remove it, tuck-point the brick and replace the crown with concrete and a 1.5" overhang, the overhang should have a groove in the underside to force water to drip instead of run back to the brick.

 

Thanks for all that info. I went back up there and see that the crown is still bonded to the top bricks. And yeah, I think that crack has been there a while.

All those steps with putting on a new crown is not anything I could do and get right so I'd need to hire someone (a mason? a roofer?). Any idea about the cost (we're in the NorthEast).

For the shorter term, is silicone caulk / backer foam in that crack in the crown and along the crown / flue junction good? Or the black roofing material I've seen in caulk tubes at home depot?

And would it hurt things to smear silicone caulk on the top of the crown and bare bricks at the top to keep off water?

After removing the moss, is silicone caulk OK to use in the cracks of the mortar between bricks? The idea is to keep water from getting in, then freezing and cracking? the bricks themselves and the mortar will absorb water, right? the silicone in the mortar would stop that in the mortar. What about the exposed brick surfaces?

 

Personally, I wouldn't want silicone all over the brick. It makes a mess and is hard to remove when it's time for the repair.

I would use a latex type caulk from the crown to the flue pipe if that is open and across that crack.

 

PJ - thank you! Not to belabor the point, but you'd opt for latex over silicone for the crown caulking also? Latex doesn't last long, right? How many years before you would replace the latex caulk?

 

I would use the caulk as a means to get to the warmer weather and then make proper repairs.

The brickwork going to need to be repointed.

 

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PJ - oh, ok. Being in NJ, any gut feel / order of magnitude what repointing and the new crown would cost? again, just order of magnitude - $50, $500, $5,000? But yeah, this is a DIY forum so you may not know. and then too, any recommendation of someone that does this professionally? I'm in Somerset county