On Jul 10, 3:16*am, David Nebenzahl wrote:
... where the rain gets in (with apologies to Lennon & McCartney).
I need to fill a hole in a garage floor. But it's an odd situation, and
I'm not sure what the proper way to do it is. I ask here with much
trepidation: tried to find answers locally, but I have no "go-to" guy
(or gal) I can get good answers to these kinds of questions from. So
I'll take my chances here. (If you *must* speculate without actually
knowing what the hell you're talking about, go ahead: I'm hoping to get
at least one or two answers from knowledgable people.)
The garage floor in question is actually above a room below. It's in a
hilly part of Oakland; the garage is level with the road in front, but
the ground slopes down sharply, and there's a room built below the
garage. (The garage is actually only a roofed area with no walls.) The
occupants are planning on finishing the room below, so this hole needs
to be filled first.
There's a hole built into the floor, apparently made for the purpose of
working on a vehicle from below. (Kinda weird, as it's almost 8' above
the floor, requiring a ladder to reach.) It's covered with a wood (2-by)
cover. The cement slab, which is about 4" thick, has a ledge molded
around the edge of the hole to hold the cover in place.
The hole is about 3 by 4 feet.
The end result needs to be able to support the weight of a person or an
automobile. It will probably *not* be driven over much (the existing
cover is never driven over by the current occupants of the house), but
it obviously needs to be able to withstand this weight.
Climate is mild, rarely freezes.
Sketches:
http://i786.photobucket.com/albums/y...aragehole2.gif
Here's what I *think* I should do:
o Drill holes into the edge of the slab, using rotary hammer & SDS bit.
o Epoxy rebar dowels into the holes, long enough to overlap at least 18"
or so. Bind the dowels together with wire. (How many dowels? spacing?)
o Add wire mesh over rebar? (What type?)
o Add new joists across the short (3') dimension of the hole, using
joist hangers, plus cleats at the edges. (The existing hole is
completely framed by joists.) Two new ones should do it, giving a
spacing of about 16".
o Place plywood (1/2"? 3/4") on top of the joists and cleats.
o Pour concrete into the hole. Finish top surface smooth to match
existing floor.
So, whaddya think? Will this work? I'm not sure I'm up to finishing the
concrete myself: learned that skill years ago on a construction crew,
but I'm not at all in practice. But the rest I can do.
--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.
- Comment from an article on Antiwar.com (http://antiwar.com)
It will be imppossible to repair this hole using concrete as any
poured
concrete will not adhere to the old and any attempt to drill holes in
the edge
for rebar to span he joint is going to weaken the existing slab.
I would use a piece of 1/4" steel chequer plate and make cover.
Make it say 2" bigger than the hole all round & weld to substantial
angles so it can't move and is rigid. . If you have a welder, a
fairly easy
task if you can get the plate cut to size, You would need to seal
it down & add insulation underneath.