I have three problems with my current shop floor that I would like to
1. Its concrete.
2. It has horrible humps and dips.
3. It slops from the house to the driveway about 3.5" total.
Research here and elsewhere has me leaning toward a simple plywood
over 2x? sleeper design. I'd like to route some dust collection and
electrical underneath as well.
I think this means I'm putting 2X? stock on edge. How should I attach
these to the existing floor? How best is the floor levelled? And
perhaps the problem that most hurts my head, How am I going to pull
the car in if I have a 6-8" step leading into the shop. ( read: Garage
I'm presently leaning toward building a "floating" grid of 2x onto
which I place 3/4" ACX and maybe selling the car. :)
Any help or other suggestions is appreciated.
On 26 Jan 2004 11:12:44 -0800, firstname.lastname@example.org (Kevin Carbis)
I don't have first-hand experince with floor making, but I took
mechanical engineering and floor design can be rather complicated.
I'd probably opt for some mats instead, in case you ever need to sell
Here is what I would do if you want flat and level with dust collection
and power for tools under the floor.
First get yourself a laser level. You will need it.
Put down a vapor barrior over the concrete. The lay presure treated 2x6
flat on the floor along one edge. The High one. Then lay another
accross the floor 8 ft from the first. Repeat till you have flat beams
accros the floor.
Now shim them till they are level with the highest. You can use asphalt
shingles as shims under the 2 bys. Once they are all flat nail them to
the concrete floor. It is best to rent a nail gun for this.
Now using these as beams Get you some 2x10 on 16 inch centers and lay
them on edge across the beams the length of the floor. With all that
nailed in place put the flooring un top. 1" 4x8 sturdy floor tounge and
grove. Glued and nailed. If you look at what you have is 2x10
supported by beams every 8 ft. For that matter 2x6 would probably be
enough. The joist will run the lenght uninterupted. It should be easy
enough to run DC and electric under the floor. The bigest problem is
the height of the floor, 13 inches above the concrete. How much
headroom do you have. You can lower that number by going as far as 2x6
on 12 inch centers. Now it is only 9 inches above the floor. If you
double up the flat beams so they are every 4 ft instead of eight you
could lay 2x4 floor joists every 8 inches and still do fine. It would
be harder to run DC under the floor but electric would be fine.
This is for discussion only. Someone with more knowlege than me will
need to size the joists. There are books you can look up the load
rating for different combinations of joist size and beam spacings.
I really like the shimming idea. I'm just not sure about the height
difference. I think Kevin still wants to be able to pull his car into the
Of course, I always look at things the hard way first.
If there is an overall slope to the whole floor, not much you can do to fix.
You may want to level out some of the dips with a floor leveling compound or
float some new portland cement. ( you can mix this yourself) before laying
down any furring strips. Then you would at least have a level surface, so
to speak, to place your wood floor. One caveat to the cement is that you
may need to break out sections to lay it in. Will not bond that well if
just floated on the suface. Not my first choice.
Other than that, a new concrete pour to level the entire surface. This
would probably require breaking out the old concrete first. I am far from
an expert here but did spend a summer laying concrete one year. We did a
few of these to repair cracked and sloping pads. One of them required
lifting the garage to do so.. (Ughh what a mess that was.)
It would simplify things if you forego the idea of DC under the floor.
While a great idea, it might not be the ticket in your situation. I don't
think you need a "level" floor, but having a "flat" floor is a good thing.
Garage floors have such a minor slope that it's really not a big deal to
leave the slope as is. However, having a flat floor without bumps/valleys
is desirable. Others with more construction experience can weigh in, but I
would think 3/4" plywood on the floor (with a vapor barrier, etc, but no
stringers) would be adequate. The plywood should be able to span any slight
valleys you have. Another idea would be to put down leveling compound then
the plywood (with a vapor barrier). That would minimize the valleys your
plywood would have to span.
Selling the car is also a good idea. Solves many problems. No more
garashop, just a shop. Extra money to buy tools. No job to go to = more
time in the shop.
Larry C in Auburn, WA
"Kevin Carbis" < email@example.com> wrote in message
Make sure you lay down vapor barrier first (plastic), then put the sleepers
on top, and shoot the same as base plates are done when you frame a wall.
Then use 3/2" plywood on top, making sure the seams lay on top of the
You can use t&g OSB (used in sub floors), but it is rough and would make a
terrible dust-catching, wood chipping floor.
firstname.lastname@example.org (Kevin Carbis) wrote in message
OK, first since you state that the garage floor slopes towards the
driveway, I can assume you have a driveway. Thus, the car issue is
solved - leave it in the driveway. Cars were designed to function
quite well outside and do not need to be put into our shop space
(SWMBO doesn't understand this as a concept, but since she gets the
rest of the house - except for about 10% of the bedroom closet space
she generously allows me to use - she allows me to use the garage -
except for the parts used for grandkids toys, the freezer, her
storage, gardening tools and supplies, the mower, snowblower, etc,
etc.). Hey, I can't help much with the floor, but if it were me I
would look at the cost (and effort) of taking out the old floor and
re-pouring at least a flat floor (it probably would still need to
slope, maybe less than 3.5"). This would probably be better for future
resell value and probably wouldn't cost alot more. I realize that
doesn't answer the the in floor dust collection and electric. While I
would like the electric in the floor concept, I don't think I would
like the dust collector in the floor - just the holes that would have
to be cut in the stringers to run 4" lines means major oversizing of
those stringers I would think.
The more I read the responses, thanks to all by the way, the more I'm
leaning toward the plywood on stringers after some minor levelling
approach. I'll run the electrical underneath but forego the dust
collection. I got to thinking that cleaning clogs in the DC ducting
would be a real pain as well.
As for the car, I suppose y'all are right, doesn't belong in a shop.
Its a convertible though and it may take me a while to get my head
around the idea of leaving it outside. Again thanks to all.
On Wed, 28 Jan 2004 00:54:49 GMT, "Larry C in Auburn, WA"
A bucki' Feamer? Feh! I kept seeing those upside down in
1-car accidents on I-5 just north of Sandy Eggo. 2 in 2
years. How does one FLIP a Beemer slowing down for traffic
on a 2-degree hill with a slow 10-degree right curve?
(I-5 southbound just north of Del Mar Heights Road)
CAUTION: Driver Legally B l o n d (e)
http://www.diversify.com Web Database Development
Driving too fast in traffic. Someone moves into your lane, you're going
too fast for the situation, swerve, over you go. Curves just compound
the situation. Sorta like 4 wheelers thinking they can drive anywhere
then end up along side the road in snow or icy conditions (I see it
every winter). Drive a fast/well-handling car and you can do anything
on the road, right? Wrong! They usually realize it when they're upside
Larry C in Auburn WA
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