Garage door framing

[TresK3]

We're having a new garage door installed, so I'm taking the opportunity to repair the bottom of the wooden door framing, which is rotting out after only 53 years. I plan to cut out the rotten parts, well up into the good wood and fit in new, pressure treated lumber. My question is about sealing the very bottom of the wood, where it touches the cement garage floor.

Should I caulk around the bottom, to try and keep moisture out, or leave the bottom edge uncaulked, so that when moisture gets back there, it has a place to go? Because I probably won't get a super-tight fit between the new pieces and the existing framing, it would be possible to leave a slight (maybe 1/16" gap) at the bottom. Or, I could make it so any gap occurs where the new wood meets old, and caulk that (planning on caulking that joint, anyway, even if it's tight).

Also, any other suggestions on filling in where old, rotten wood was, would be appreciated.

TIA,
Tres

 

[gzecc]

Give us a picture please.

 

[semipro]

I would not place your new wood near the ground without some waterproof layer underneath. Maybe RTV silicone would work to separate the two? With a gap I'd be concerned that dirt would gather there, bridge the gap, collect water, and rot the wood (yes, even if treated wood).
If you can match the look of the grain and such I'd suggest you use PVC boards in lieu of the treated wood. You may have to take 2 3/4" trim boards and glue them together to get the right thickness.

 

[Highbeam]

Another wood board in the same spot may last another 53 years so put it back just as you removed it.

 

[KB007]

When I re-did our garage doors, I just pulled off the old frame and replaced it with PT all the way around. Seams look ugly and scream that a DIY guy who was too cheap to buy a full piece of lumber lives here.

As for the bottom, either leave an air gap or caulk / silicone the bottom and leave an air gap. You need space at the bottom to allow the boards to expand and contract. Do not cut it and have it hard to the ground, as when it expandes it can do all sorts of wonderful things.

 

[btuser]

They make a product for sealing sills, other than that I'd put a bead of silicone on the inside (upside of slope) to keep water rolling under and to seal any drafts. PT will last a long time in direct contact with concrete.

 

[sportbikerider78]

RTV'ing to wood is a joke. If anyone thinks they can seal a porous material with a non-porous one, I have a good deal on a bridge in NYC for them. ;-)

If it was me, I'd use some flashing just like pressure treated lumber sits on a foundation. You may or may not be able to hide it.

For the trim around the door, buy the fiberglass or plastic stuff. No paint and it looks good.

Pics are always good.

 

[semipro]

The quality of new growth lumber is not what it used to be 50 years ago, untreated or treated. I've personally witnessed what many others report; newer PT lumber does not hold up like the older arsenic treated stuff. Code requires any wood that contacts masonry be treated. I always take it a step further and install a water barrier, usually a foam sill seal. I wouldn't do that on garage door trim though as its exposed and would trap water and look bad.
Having a house covered by cedar, I can also attest that RTV silicone will seal end grain well. Its been doing it well on our trim for over 25 years now. Whenever I pull a piece off to repair I'm amazed at how well the silicone still adheres and seals.

 

[Hogwildz]

We're having a new garage door installed, so I'm taking the opportunity to repair the bottom of the wooden door framing, which is rotting out after only 53 years. I plan to cut out the rotten parts, well up into the good wood and fit in new, pressure treated lumber. My question is about sealing the very bottom of the wood, where it touches the cement garage floor.

Should I caulk around the bottom, to try and keep moisture out, or leave the bottom edge uncaulked, so that when moisture gets back there, it has a place to go? Because I probably won't get a super-tight fit between the new pieces and the existing framing, it would be possible to leave a slight (maybe 1/16" gap) at the bottom. Or, I could make it so any gap occurs where the new wood meets old, and caulk that (planning on caulking that joint, anyway, even if it's tight).

Also, any other suggestions on filling in where old, rotten wood was, would be appreciated.

TIA,
Tres

Those that can't get silicone to adhere well, don't take the time to tool it in.
Tooled in well, it will stick to just about anything well.
Another option mentioned would be to cut the rot out, replace with the wood as you plan, and cap the wood & trim with PVC coated trim coil capping.
A small bead of silicone or my favorite...urethane caulk, tooled in at the bottom where the wood &/or capping meets the concrete, and you won't touch it again in your lifetime.
Skip the plastic crap trim, if it gets any sun, it will warp, buckle and look like shat.

 

[sportbikerider78]

My point about RTV is that wood is porous. It absobs water. It might do a great job filling a gap, but it will not seal because the wood will absorb the water anyway.

It has its place....but in many cases you are going to just prevent the wood from breathing properly instead of drying out.

We get TONS of rain were I live and my home is in a worst case type of situation.

Most trim is the cheapest pine you can buy. That is truely crap.