Hello,
I have 2 doors, both on the basement level or a walkout basement, that have aluminum thresholds that are bowed up. It is the worst in winter when the bow in the middle is about 1/2″. It seems like the width of the doorway is too small and is forcing the middle of the thresholds up. Does anyone have any idea what could cause this. We have another door on the same side of the house that opens onto the deck and doesn’t have the problem. Our builder cannot figure it out.
Thanks, Eric
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Replies
You saying the problems comes ands goes with cold weather?
Maybe a moisture problem under that door, and the water freezes and bows the aluminum.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
the bow is about 1/8 inch at the least and 1/2" in the winter.
If that's the problem, the solution is to remove the threshold and shorten it a half inch or so.
But I doubt that that's the problem. More likely the floor is heaving slightly.
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the floor is concrete basement floor and I don't see any way to remove the threshold.
You'd think the alum threshold would shrink in cold, not expand and be bowed.Perhaps the temp differemntial between inside and outside is creating an unusal sub-threshold harmonic frequncy tone which is summoning the mothership?I'd consider changing it to wood.
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I have looked at the problem more closely and have found the following: The doors are prehung Thermatru units with aluminum sill with wood underneath it. The sills are sitting on top of the concrete foundation wall. I'm not sure why the sill is bowed in the middle, but I can see that there is no caulk or sealer between the sill and the concrete. This made me rememer that I have seen water seep under the door in the past. I'm guessing that this water is seeping under the sill and freezing in the winter, forcing it to bow more.
Actually, I found on the Thermatru website that if the sill is bowed up to screw it down.
It seems that I have to remove the sill, put down caulk/sealer, reinstall the sill and screw it down into the concrete with anchors. The problem is that I'm not sure if I have the skills to remove the sill. It sits underneath the door jambs. If i remove the jambs, does anyone know if there will be horizontal screws/nails fastening the side frame to the sill? If so, any good ways to cut them? Hacksaw?
Thanks for your help so far! You've helped me go a long way in figuring this out.
Eric
You really only want to caulk along the outside edge anyway -- should be able to dig out a slot about 1/2" deep under the threshold, using something like a hacksaw blade (and maybe an old paring knife). Get it clean and dry and then caulk. Just force the caulk in about 1/4 inch.
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Well, here's what I did. I ended up taking out the whole prehung door unit. It was pretty easy, especially since it's my first time. It was difficult to pry off the exterior casing since I have vinyl siding. It was also difficult getting it back into position. I should have marked the floor first! I caulked well underneath.
The hard part was drilling holes in the concrete in order to screw down the sill. The crappy bit from the hw store lasted 5 minutes. I used 2 bits for 2 holes at $5 each. I screwed the sill down with blue concrete screws and it cinched down really well and got rid of the upward bow.
Unfortunately I had to remove the concrete screws in order to adjust the door frame to make it close correctly. So now I have to go back and get more bits and screws tomorrow.
I'm kind of glad that I did this because I found a hole at the bottom of both vertical exterior casing pieces that was letting all kinds of bugs and moisture into the space between the jamb and the stud. I plan to seal that up and fill in all of the gaps with low volume expanding foam made for windows and doors.
Yes, my builder should have taken care of this, but it would have taken weeks or months. I'm glad that I was able to take care of it and learn something in the process. Thanks to all of you for your help!
Eric
You can always remove the threshold -- just takes a little creativity (or maybe a big crowbar). Sawzall blade between threshold and frame will often loosen it up.
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Screw the thresholds down to whatever is below them?
eric, I'm assuming this is a new const. prehung unit. There's the old alum thresholds with a wood backer underneath the alum and now offered are composite backers. You could cut the old thresh out, replace with the new style which would not be susceptible to moisture pickup and expansion. You'd have to screw the thresh to the concrete through which can be done with stainless screws and plastic anchors. While you're at it, get some new door bottom sweeps from the original door unit manufacturer and replace those as well as they might be worn at the high spot. Most are held to the door bottom with barbed legs set in two grooves in the door (that's why OEM is a good idea for placement of the grooves). Probably a couple of staples on either end.
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