# Best material to fill gap under exterior door? Mortar?



## joecaption (Nov 30, 2011)

Got a picture?
Old concrete does not like to stick to new and a thin layer is likly to just crack.


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## mikegp (Jul 17, 2011)

I can get a pic. This would be on top of the asphalt, which I'm sure shrinks and expands, plus it dries out. I can't think of anything else to put there. Maybe some type of rubberized sealer?


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## joecaption (Nov 30, 2011)

That concrete sounds like it was pored wrong in the first place. It should have been pored so it came out to the outside wall so there would be a soild surface under the doors threshold.

What I've done, right or wrong but it worked fine and is still solid years later is before the door went in I used a piece of wood that was ripped to width to make the opening level, I used a few dabs of PL adhesive to hold it in place and back filled with Hydrolic cement mixed up soopy.
Got to move fast because it sits up so fast. One it hardened pry up the piece used to form the dam.
Now the threshold has 100% contact.
The door needed to be set in a bed of silicone on set in a sill jamb to keep water from getting in under it. The way you have it now that's not going to happen.


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## mikegp (Jul 17, 2011)

It wasn't made to have a door put there, it was originally meant to stay open. I don't even care about water because water gets in there somehow from the top and moisture builds up that wicks through the concrete. It's really just to store some random stuff and a few sets of wheels/tires. Hydrolic cement in a pastry type bag should work, no?

As of now I just filled the gap all the way around with great stuff to keep bugs out. Those really fast centipedes are squeezing in there somehow. I found about 20 in there the other day.


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## joecaption (Nov 30, 2011)

It's to late now if you have used the foam. That stuss stick to everything and is impossible to clean it out without removing the door.
Hydrolic cement hardens up so fast there's no way to mix it and get it in the bag without it setting up.
About all you could do now is rip a piece of vinyl lumber and tap it in place, that would not rot and would support the outside edge of the threshold.
With just foam under it that threshold it's going to bend and crack the caulking seam on the outside edges.
Really need to take the time and figure out why that waters getting in!!
If that type bug is getting in there there not going away until the moisture problum goes away.
To kill them get yourself some Roach Away. It's 95% boric acid.


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## mikegp (Jul 17, 2011)

The water and bugs aren't a big deal. Just want to get something under the door so it looks finished. The opening is larger on one side so getting something solid in there will be tough. 

I'm really trying to use something that can be squirted in somehow.


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## mae-ling (Dec 9, 2011)

you need to rip the vinyl lumber on an angle or plane it or sand it.

Can't think of anything that you can squirt in that will be solid and not just crack up later.


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