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Sagging threshold after removing laminate floor.

Sagging threshold after removing laminate floor.

Old 10-09-07, 01:34 PM
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Unhappy Sagging threshold after removing laminate floor.

Hello all...I have a few questions here after removing an old laminate floor and the vinyl flooring that I found below. After getting down to the subfloor (to prep for new wood flooring), I found a small water mark close to the French doors in my dining area. I also now have a sagging metal threshold and can feel a breeze coming into the room from outside. My questions are:

1. What is the best way to fix the gap/sagging issue (shims, composite piece to fill section under doors)?
2. Besides insulating foam, should I use some other method to insulate/water proof this area?
3. Although the subfloor is not rotted or seems to have lost structural integrity, should I consider replacing that section of flooring prior to having the new wood floor laid down?

Thanks to all for reading and responses.
Old 10-09-07, 03:29 PM
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If the subfloor shows no signs of rot or water damage, first shim the threshold at 2-3 places, then use, non-expanding foam(DAP or similar) under the threshold. Caulk the outside with silicone or urethane caulk.
Old 10-09-07, 04:35 PM
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As mentioned, you probably want to insert some shims under the door to take up the gap and provide good support- especially where someone would step as they walk through the doorway. You especially want it to feel solid where people step, so you might put a couple more shims there than you normally might under the non-operating door.

If you insert a thin shim (1 1/4" wide or so) here and there, you will have enough room to use expanding foam under the door. Foam is not the best thing to use to stop a leak, but apart from taking the entire door out and reinstalling it, I'm not sure what other options you have. You'll want to use Great Stuff Door and Window foam (blue can) not the Great Stuff in the red can. You can also use Dap Latex Door and Window Foam, which works well in very narrow gaps. (although the can doesn't work too well when it's half empty and you tip it on it's side to spray.)

If you'd like to track down where the leak might be coming from, you could also inspect the exterior of the door to see if it needs to be resealed, or if there are gaps around the trim. Youd start looking at the bottom of the door. If there is an apron under the door you could also remove that bottom piece of exterior trim and see if you can seal the bottom up better from outside, using flashing membrane tape. If the door has trim on the sides and top, you could also remove the trim and possibly install a flashing membrane tape over the nailing fin (if it has #908 brickmould it might not have a nailing fin). Sealing behind the trim is potentially better than running a bead of caulk around the perimeter or across the front of your threshold, since if you have some water that is somehow coming down the wall and into the rough opening from above, a bead of caulk in front of the threshold could also act like a dam, prevent it from draining outside , which might cause that water to back up onto your floor. Doing things that might prevent water from getting into the rough opening in the first place by using flashing tape is IMO the best practice to stop leaks. Stopping it from getting to your finished floor with foam is good, but not if it's doing hidden damage to the subfloor underneath your door.

Regarding the subfloor, if it's solid you have nothing to worry about. Your new floor will go down just fine. And if it's still solid, I doubt you have a major leak on your hands- just the occasional gale force wind blowing a little water into where it normally never gets wet.

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