Got a sticking situation....REALLY !!!

[JDgreen227]

I am planning to stick a 14 inch square section of galvanized flashing to part of a brick chimney that is pretty much bare brick and mortar, only the slightest trace of faded paint, and the chimney section has been powerwashed and given ample time to dry. If I am using one 10 ounce tube:

How many of the guys here say the most effective product for the purpose will be ordinary roofing cement, and how many say PL 400 construction adhesive for decks will have a stronger bond?

 

[Bird]

I don't know anything about the PL 400, but because of good past experience, I'd probably use Loctite Power Grab All Purpose Construction Adhesive. And of course the PL 400 is also a Loctite product, so for all I know, it might be even better than the one I do have experience with.

 

[JD435Bill]

I would probably use neither. When it's flashing around a chimney, I like to both embed it into the mortar joint and weave it in with the roof shingles. Anytime I need to "attach" it, I like using anchors and stainless steel screws. Maybe what you are doing is OK, but it's hard to say without pictures. Also galvanized can also rust in time.

Bill

 

[dave1949]

I glued my pine baseboards to primed plaster with the Loctite Bird noted. I was impressed with the grab and hold that stuff has. Neither the walls or the boards were perfectly straight. I did apply as much pressure as I could with heavy stuff pushed against it for 24 hours.

 

[JDgreen227]

It's kind of a unique situation...maybe the pics will help illustrate my query. The section of roof the chimney is near has a layer of premium shingles only 7 years old. There is a primary roof overhead which drips some water onto the lower roof, and that water wicks lengthwise toward the house siding and sheathing, and there is often a strong wind coming from the east that blows the water onto the chimney bricks. Another picture shows the section of heavy duty galvanized metal I have cut and bent to use as flashing after removing part of two shingles and the siding. While I can nail the flanges to the 3/4" plywood sheathing, I want to stick the vertical 14 inch square of galvanized steel to the chimney bricks. The galvanizing is VERY heavy...a section of 40 year old heating return duct. As JD435Bill noted, the preferred method is to embed it in the mortar joint, but I don't really want to chip out 60 year old mortar. One picture shows the chimney area before I wirebrushed and powerwashed the bricks and removed part of the shingles.

 

[TCJatko]

You need to get the flashing to go around the corner and up the side of the chimney to get a good seal. Maybe something soldered up out of sheet copper? Also, the flashing going up the roofline seems to be just sitting on top of the shingles. It is providing NO protection of the joint that way.

 

[SPIKER]

I dont have pics but just "Re-Roofed" our place. The chimney was one of the areas giving us trouble as the top has all loosened up and was channeling moisture down the flue and out into attic. I dont think the flashing was actually leaking but ended up re-flashing it with the new roof.

I used the "Black Jack" type roofing sealing between the old & new flashing as well as used it to attach to the brick.

I had to chip & re-lay the crown and top 4 rows of brick as the 80 yr old mortar was too bad of shape to leave it long term. I bent the NEW flashing to fit added the sealant and used 2 cheap blue ratch straps to hold it in-place for a week or two while it all set.

DONT use the PL400 or PL200 they are not really weatherproof or UV inhibited & will dry out & crack. Not a lot will stick to Galvanized metal real well but most of the Roofing Cements should work Better than the PLs

Mark

 

[hosspuller]

IMHO ... metal and brick have different rates of expansion. Trying to stick one to the other is just asking for trouble. Chimney flashing is even a worse case. The building roof moves in relation to the chimney. It is better to allow the movement with step flashing covered with counter flashing. Cut a groove and bed the counter flashing to the brick.

 

[JDgreen227]

Thanks to everyone who provided feedback and information...my situation here is really unique and I wanted to get outside information from the experts...learned a lot from everyone....THANKS TO ALL !!!

 

[KENSFM]

I would not use galvanized steel, it will rust in time and leave a stain on your shingles. I think aluminum, copper, or lead would be better choices.
Ken