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rwalker28 01-04-2009 01:22 PM

Old Furnace Closet Refurbishing Question
We had an old Lennox furnace that was located in our house replaced with a gas pack/ac combo on the roof (I am in Phoenix, AZ). I want to clean up the old furnace closet. We have a house built on a concrete slab (common in Az) and it was built in about 1952. There are three pipes in the floor of that closet where the old furnace was removed from, one is a drain located roughly under where the double wall vent pipe is located in the ceiling - very rusty in side. the other two pipes go down about 8" into the slab on the other side of the closet. When I put a wire in the two pipes on the other side of the closet and peer down with a flashlight, it looks like they go somewhere, the wire does find an elbow down there in those two pipes, but they dont look blocked and are not rusty. These two pipes I mention were never connected to anything when we moved it (it may have been for a previous furnace that was removed, but who knows...) The first pipe i mentioned i cant tell if there is an elbow at the bottom, it is very rusty inside and full of rust flakes and hard to see and when we moved it it was connected with a plastic pipe to the furnace, if memory serves correctly, but I think this drains to the outside. My questions is, can I cut off all those pipes at floor level and fill them in with grout since the furnace is gone? I think they are just ways for bugs and geckos to get into the house. Many thanks in advance, bob walker, phx az

glennjanie 01-04-2009 05:53 PM

Hello RWalker:
Yes, cut them all off flush with the floor and fill with grout.

rwalker28 01-04-2009 06:54 PM

Thank you for the quick reply, Glenn. I don't like to make "permanent" changes without expert advice. bob walker phx az

inspectorD 01-04-2009 08:18 PM

Before you install the grout, you can put some expanding spray foam in a can down there to keep the joint sealed. This stuff is great, it's actually called great stuff. And it sticks to everything. When the grout shrinks you may have a small crack and this will help in the long run. It will also keep the grout from continuing to run down the pipe. Then you will need only one batch instead of two.:D
Good luck.

rwalker28 01-04-2009 09:28 PM

Thank you inspectorD, i was just going to make up a bunch of mortar mix and stuff it down there until no more would go down. But then I had a another question. I intend to put down wood floors (laminate likely, haven't decided.) Is there any preferrable way to plug these holes with that in mind? The expanding foam idea is excellent. best regards, bob walker, phx az

inspectorD 01-05-2009 07:49 AM

I think what you are doing will be fine. These pipes are probably part of a closed loop system and do not go anywhere except return to each other.
If you have a concrete floor, I would put down plastic first before any wood. The good thing about prefinished floors is they are removable because they only snap together and are free floating.
Unless you have alot of flooding you should be fine.

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