Flashing - how to requested

Icefishww

Will someone give me advice on flashing this roof line once I get the T1-11 patched and covered with felt. What I have planned is to eventually cover the T-1-11 with f/c lap siding. First I plan on putting in the step flashing and then a trim board that will cover the verticle leg on the step flashing and run up to the ridge. Would my best bet be to then form a run of continuous metal flashing lapping the top edge of the 1x trim and then paper and side over that? The previously owner just caulked the top edge of the old piece of trim and that was what leaked and caused all my problems.

thanks -

Attached Thumbnails

 

troubleseeker

Not sure what you mean by fc lap siding (factory coated?) but I'd suggest doing away with the trim board you propose, as it just creates a water trap. Flash, then just cut the ends (and seal) of the siding parallel with the rake of the roof, holding it about 1 1/2" above the roof .

If you really want the trim board, you will have to cap the top edge with a Z shaped flashing to waterproof it.

Looks like you caught this one in time. Am I missing something in my interpretation of the photo; it appears that there was not any flashing before.

Icefishww

F/C meant fiber cement and it is the horizontal lap siding 7-1/4" variety. There was step flashing before and a trim board that covered the vertical leg but the caulking came apart and in addition the T1-11 was never maintained. It's old but overall in good shape so I'm thinking I'll just replace the bad cut outs with OSB and side over it. I wanted to make sure I don't screw up on the flashing because I'm somewhat new to this,

tks,

troubleseeker

Daah..sorry for the brain fart. I'm so used to generically referrring to this as "Hardi siding" , that "fiber cement" just did not trigger any brain activity.

I'd cover the T-111 with felt or Tyvek before installing the fc, be sure to leave the recommended gaps at seams and corner boards, install felt splines under the butt seams, and use a high quality sealant, not just regular latex painter's caulk. We use an acrylic urethane manufactured by SiroFlex; this is the same stuff used to install vinyl replacement windows, and is some tough.

Your note that the "caulking came apart" is exactly why you must flash for waterproofing, not caulk. Caulking is a temporary solution to a permanent problem.

buletbob

Say Ice fish. Being your going to install the f/c siding . What I would do is leave the 1x trim off. install step flashing over the T1-11 after you make the repairs, Cover the top with some ice shield or grace-shield , house wrap and then install the siding. It will look a lot cleaner and less chance of a leak later on down the road. BOB

Icefishww

Never even considered leaving that trim board off........best thing I've heard in a long time.

Another thing I'm wondering about is building a rain screen on the weather sides of the building ( south and west). Do you have any thoughts about that? Not sure if I'd have to re-install the windows though.

buletbob

I'm not sure what you mean by rain screen??? BOB

ccarlisle

Go to the "Roofing" section and ask there...ask for 'Grumpy' or Ed

Icefishww

By rainscreen I mean attaching the siding to furring strips so that a cavity is created between the siding and the wrap. A way for the water that gets in to get out.

buletbob

Its not necessary to install the rain screen as long as you install the siding to the manufactures spec's. By adding the rain screen you'll be bringing the siding out past the window casing. just install the house wrap seal ALL seams and flash all butt joints and back caulk all windows and install metal drip caps. GOOD LUCK BOB