Sorry... kind of a long winded poster here. I live in rainy Vancouver
in an old house that has poor drainage. We had a big storm yesterday
with enough rain to keep the basement sump pump going frequently until
late evening. I've been thinking of using my attached garage as a
workshop and today while cleaning out some junk I found small puddles
underneath some non-porous items lying on the floor (buckets, plastic
garbage bags etc). It seems there was enough moisture under the
concrete slab that some migrated up to the top and condensed in these
few spots. This has happened a few times before during these really
intense downpours we get 3-4 times a year.

I dread the thought of digging up around the garage perimeter to
attempt fixing or enhancing the existing drainage system. Will this
periodic excess moisture present many problems in the shop, even with
good heat and ventilation? I've been thinking of laying down a wood
floor anyway because the existing slab is quite sloped, so any power
tools I plan to buy would be a few inches above the concrete.

Your suggestions and comments would be appreciated.

Glenn
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Glen,

The moisture you found under the items (buckets, etc.) is evidence that the
floor has probably never been sealed. All cement floors will wick moisture
to some extent and its the sealer that prevents it from getting thru. Use a
cement cleaner and then apply the best concrete sealer you can find for aged
concrete. This needs to be a sealer, a topcoat of some floor paint (that
isn't a sealer) will soon deteriorate and peel.

As for digging up around the garage perimeter - first find the source of the
water. Is it because of a lack of rain gutters or bad drainage (look up
French Ditch).

Bob S.

Glen,

An un-related thought here...

If your going through the trouble of putting in a wood floor, you might want
to consider making it about six inches from the concrete if you can spare
the head room. This will allow you to run wiring and/or ductwork (for dust
collection) under the floor to those 'middle of the shop' machines like your
table saw.

Of course, this is assuming your planning on a permanent garage shop. You
know, without those pesky cars getting in the way!


"gh1[n??????????? wrote in message
...
Sorry... kind of a long winded poster here. I live in rainy Vancouver
in an old house that has poor drainage. We had a big storm yesterday
with enough rain to keep the basement sump pump going frequently until
late evening. I've been thinking of using my attached garage as a
workshop and today while cleaning out some junk I found small puddles
underneath some non-porous items lying on the floor (buckets, plastic
garbage bags etc). It seems there was enough moisture under the
concrete slab that some migrated up to the top and condensed in these
few spots. This has happened a few times before during these really
intense downpours we get 3-4 times a year.

I dread the thought of digging up around the garage perimeter to
attempt fixing or enhancing the existing drainage system. Will this
periodic excess moisture present many problems in the shop, even with
good heat and ventilation? I've been thinking of laying down a wood
floor anyway because the existing slab is quite sloped, so any power
tools I plan to buy would be a few inches above the concrete.

Your suggestions and comments would be appreciated.

Glenn
{Please remove the [nospam] for email replies}

My parents garage also had a moisture problem like that. In the summer, I
would leave open the hatch to the insulated attic, and the convection would
keep the floor very dry. I never did come up with a good solution for the
winter. Neither could I explain the cause of the moisture. The garage was
well above grade, and the lot sloped away from the garage.

"gh1[n??????????? wrote...
snip
I dread the thought of digging up around the garage perimeter to
attempt fixing or enhancing the existing drainage system. Will this
periodic excess moisture present many problems in the shop, even with
good heat and ventilation? I've been thinking of laying down a wood
floor anyway because the existing slab is quite sloped, so any power
tools I plan to buy would be a few inches above the concrete.

Aside from any other suggestions you get, if you place a wood floor down
over the concrete, make sure you use a vapor barrier. I would even make
sure that the edges of the plastic sheeting (where two sheets meet) over lap
with plenty of room to seal them with a couple beads of silicone. Of course
the fact that Bob's advice on finding the source is excellent goes without
saying. I just wanted to throw in the idea of a well sealed vapor barrier.

--

Cheers,
Howard

----------------------------------------------------------
Working wood in New Jersey -
Visit me in the woodshop - www.inthewoodshop.org

I would use a combination of the solutions, I would seal the concrete,
use a vapor barrier and seal it with silicone and then drop in your
floor of choice. Anything from 1x on flat to 2x6 on edge if you have
the room.

If dampness is still a problem, you could resort to a dehumidifier but I
doubt that you will see a need for that.

BRuce

wrote:

Sorry... kind of a long winded poster here. I live in rainy Vancouver
in an old house that has poor drainage. We had a big storm yesterday
with enough rain to keep the basement sump pump going frequently until
late evening. I've been thinking of using my attached garage as a
workshop and today while cleaning out some junk I found small puddles
underneath some non-porous items lying on the floor (buckets, plastic
garbage bags etc). It seems there was enough moisture under the
concrete slab that some migrated up to the top and condensed in these
few spots. This has happened a few times before during these really
intense downpours we get 3-4 times a year.

I dread the thought of digging up around the garage perimeter to
attempt fixing or enhancing the existing drainage system. Will this
periodic excess moisture present many problems in the shop, even with
good heat and ventilation? I've been thinking of laying down a wood
floor anyway because the existing slab is quite sloped, so any power
tools I plan to buy would be a few inches above the concrete.

Your suggestions and comments would be appreciated.

Glenn
{Please remove the [nospam] for email replies}

--
---

BRuce

Glenn;

Sounds like you need to look after your perimeter drainage problem before
you consider laying a wood floor. Otherwise the moisture will warp your
floor.

In my house I had puddling in my crawl space. I replaced half the
perimeter drainage about 8 or 9 years ago when doing a backyard patio
project. That cost about $10,000. Still had puddling and finally did the
front half a year ago for another $10,000, including new front stoop,
sidewalk and a strip across asphalt driveway.

Now, a year later, the puddling is gone from the crawl space and a moisture
test indicated that the main floor is at a moisture level ~12% (was over
20% a year ago). At that time a floor installer warned me that he would
NOT install wood flooring until the moisture problem was solved.

Next door, a new neighbour installed wood flooring right after buying the
house and without the installer checking moisture concerns. A short time
later it started to warp. Need I say more!

Brian

|
| Sorry... kind of a long winded poster here. I live in rainy Vancouver
| in an old house that has poor drainage. We had a big storm yesterday
| with enough rain to keep the basement sump pump going frequently until
| late evening. I've been thinking of using my attached garage as a
| workshop and today while cleaning out some junk I found small puddles
| underneath some non-porous items lying on the floor (buckets, plastic
| garbage bags etc). It seems there was enough moisture under the
| concrete slab that some migrated up to the top and condensed in these
| few spots. This has happened a few times before during these really
| intense downpours we get 3-4 times a year.
|
| I dread the thought of digging up around the garage perimeter to
| attempt fixing or enhancing the existing drainage system. Will this
| periodic excess moisture present many problems in the shop, even with
| good heat and ventilation? I've been thinking of laying down a wood
| floor anyway because the existing slab is quite sloped, so any power
| tools I plan to buy would be a few inches above the concrete.
|
| Your suggestions and comments would be appreciated.
|
| Glenn
| {Please remove the [nospam] for email replies}
|
| --
| ---
|
| BRuce
|