Contractor Talk - Professional Construction and Remodeling Forum banner

Fiber Cement Joint Flashing

25722 Views 38 Replies 25 Participants Last post by  FrankT
What do you use for joint flashing of fiber cement siding? Anyone use this product: http://www.theprolineseries.com/ Is it a good additional measure to channel wetness from ever getting behind the siding? Would the thickness of the strips cause problems for some reason?
1 - 20 of 39 Posts
We use pieces of felt. But then again we use felt here as our house wrap as it's the only thing that works.(around here) We back caulk as well. It it's the felt that does the work. Does a great job of keeping water from getting behind your siding below.

I do see plenty of jobs around here that do just rely on caulking and it makes me cringe.
Somewhat off topic, but can you elaborate on why felt is the only thing that works for WRB for your region?
Way too much moisture. They have newer products that work that are essentially a Tyvek type material with the drainage lines weaver in and a felt over the top. Tyvek just doesn't stand up here. No local suppliers even carry it.

You can use Tyvek, but you better put felt over it around here.
During install we use the "rain drain" house wrap. It has a string about ever inch apart running up and down to allow water drainage.

On the seem I like the metal flashing like shown in the link minus the foam strip. I like the idea though.

Side note trick. .....If your helper forgets to add the butt seam flashing and nails the end. Instead of trying to remove the nail with high risk of damaging the board. Just use a punch and drive the nail in further into the structure (enough to let the flashing slip behind and not drive it so far as to create a hole in the house wrap and be able to hang a picture on the inside sheet rock) then flash and renail end.
we just use felt paper, on one job we were using the scraps of aluminum coil stock and the peices that were damaged just to use it up
I use coil stock, I have piles of scrap
I used to use felt, but then I read somewhere that you shouldn't because when the gap opens the felt is exposed to the sun and can deteriorate to the point of failure.

I'm sure most would argue the minor sunlight is inconsequential, but it made enough sense to me that it could happen over 30+ years of exposure. I now use aluminum. Easy to cut pieces to size from leftovers. It only sucks keeping a stack of squares in your pocket because it guarantees you'll slice yourself at some point.

I'm not sure where I read this, but I think it might have been a Mike Guertin article. I'll see if I can dig it up when I have more time and not reading CT on my phone at lunch.
  • Like
Reactions: Tom Struble
The last time we used FC siding, we used 3 by 5 step flashing between the joints. As well as spray painting the flashing with a color close in color with the siding.
make it where you don't have any butt-joints
Where do you get 100 foot long boards? Are they light and easy to carry? Lol
make it where you don't have any butt-joints
Has anyone tried the Bearskins yet? http://www.bearclip.com/Install Bear Skins.htm

I was at a presentation from Certainteed and was told about them, but had never seen them. We had always been using step flashing, which apparently was a big no no. Never knew that either.
We did a hardie job. Pre-finished white siding. We used the white vinyl or plastic rolls of flashing. Just made up a bunch of flashing cards on the break. Worked really well.
We used tyvek squares with a littlecolor matched paint once, but mostly use tar paper
I'd never use tyvek or tar paper. Tyvek is suspectable to UV and i'd be afraid tar felt would bleed down onto the panel.

Color matched coil stock is typically what we use. You can make 360 5x8 cards for around $80 plus an hour labor. We typically have a scrap rolls that are a close match so essentially it's a win win. Clean out the shop and save a couple bucks.

If I was in a high rain driven area like beach front It would probably be worth the investment for the pro line cards that are referenced in the first post.
We use the Bearskins,...I like them...( plus it's a cool name ) :clap:
I've used the bear skins....didn't stick great but did the job. Clips on the pouch...kind of
For some reason I heard that fiber cement shouldn't be used with aluminum trim/flashing. I used galvanized coil behind my joints and caulked (the one time I installed FC) Anyone else heard they're incompatible?
woodworkbykirk said:
we just use felt paper, on one job we were using the scraps of aluminum coil stock and the peices that were damaged just to use it up
I sure hope not. I've always used aluminum (including when I did my own house 10 years ago) and haven't ever had a problem.
For some reason I heard that fiber cement shouldn't be used with aluminum trim/flashing. I used galvanized coil behind my joints and caulked (the one time I installed FC) Anyone else heard they're incompatible?
I'll go under if so....

I like coil stock and a rattle can.
dielectricunion said:
For some reason I heard that fiber cement shouldn't be used with aluminum trim/flashing. I used galvanized coil behind my joints and caulked (the one time I installed FC) Anyone else heard they're incompatible?
1 - 20 of 39 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top