I’m going to install a bathroom vent this weekend (I hope) and run the exhaust out the gable end wall of my house. I was planning to use a hole saw to get a hole for the hood into the wall. The house wall is :
vinyl siding – (maybe old wood siding?) – building felt – solid wood sheathing – attic.
Any tips on how to do this? Will the hole saw go through it all and should I seal the builing felt back down to the wood with something?
Should I score the vinyl first or cut that by hand?
Thanks!
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Replies
I've used a hole saw for just that. It takes about a 4-1/2" hole to fit everything. You'll probably have to drill thru one layer at a time, cleaning out the build-up in the bit as you go. The hole saw goes thru the vinyl very easily.
If you are really concerned about drafts in your attic, use a little expanding foam on the inside to seal it.
a warning- a hole saw that size tends to grab if you wander off line even a bit. I've been thrown off a ladder drilling holes that way when it jambs and the drill keeps moving. Be careful, make sure you have someplace safe to work, and it'll go fine.
You mean if I twist the drill from perpendicular to the house, it'll seize up? Thanks for the tip. I'll be on a ladder. I'm not sure my drill (15V craftsman) is strong enough to throw me. I'll make sure DW is there to catch me ;)Should I drill from the inside where there's cushy insulation to land on?Gotcha on the foam - just got my Todol gun this morning.Thanks for the tips.
Be sure you use a side handle on the drill. It'll help control it when it does grab.
I usually drill a pilot hole, the size of the guide driil on the hole saw, first, all the way thru the wall where you want the hole to be. That way you can check out the final location and make any adjustments.
And I do prefer to drill from the inside if there's room to work. Its a little safer.
And are you really sure yer better half's gonna catch you if ya fall? She might be looking forward to spending that insurance money.
Should I drill from the inside where there's cushy insulation to land on?
You can, but I would stop drilling from the inside when you get through to the vinyl. Then, I would go outside, and drill through the vinyl from the outside in. This way there is less chance of pushing the siding off the house.
Rent a hole hawg, or other SLOW speed drill. Well worth the $20. It will cut through like butter. Your Craftsman will be an exercise in futility.
Drill the pilot hole first, from the outside, so that you can get it properly placed relative to the pitch of the siding. Then you can drill from the inside.--------------
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Just finished the job after much delay. Thanks to everyone who replied. I did a pilot hole from the inside, moved to the outside and re-centered so I'd get the drip edge from the shingle above. Did a pilot hole and then cut the siding in reverse. Man, am I scared of being on that ladder. Then went inside and completed the hole. Outside I used some foam-rubber gasket to fill in some gaps around the vent and probably too much caulk. I primed the inside of the hole, just in case.I really appreciate the replies, especially to Shep for the warning about being thrown from the ladder (I would have been for sure after having used the hole saw), BigMan for the tip on reversing the drill to cut the siding, and DanH for the drip edge idea.I haven't foamed yet - I want to let it rain first and see how I did with the caulk and gasket. BT is great but I really appreciate it when I can see it help me do a job safer. The ladder was scary enough without trying to control the hole saw on it.
Try to plan the hole so the top lip of the outside hood will fall just under an edge of the siding. This lets the siding do a "flashing" job for you.
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Drill a pilot hole first, check for clearance, use the holesaw from the exterior, running drill in reverse to cut the vinyl, very smooth cut, no grabbing and makes a perfect hole even when its cold out, then switch to forward and complete the hole.
I'll try to avoid bridging two pieces of wood sheathing (I think they are 1x6s), but if I have to, is that okay?I don't need to seal the felt back down to the house somehow?
Bridging the sheathing joints generally won't hurt. In fact, it's probably better to bridge than to take out virtually then entire single piece with a centered hole. Obviously, avoid any framing if at all possible.It would be ideal if you could get a seal between the felt and the vent pipe, but that's difficult to accomplish. You can seal the felt to the sheathing with a bit of caulk or construction adhesive, to slightly reduce the chance of getting rain behind it.If possible, foam from the inside around the pipe after installation with a LOW EXPANSION ("door and window") foam, being carefull to not blow very much behind the vinyl -- you don't want the foam to push the vinyl out.
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