Fixing floor slope prior to Race Deck

[JohnnieMo]

I have a double garage which I'll be adding a small extension to the front (opposite to door) to create some more working space.

One problem I have is the existing slab is about 25 years old and is high in the centre. As a result, all the water flows to the sides and mostly to the front. The walls are slowly turning to dust and I'm working in puddles all winter. Then the puddles will with saw dust and make a sludgy mess.

I'm doing a build out of the garage and giving it a facelift. I'm considering flooring options and I like the Race Deck option. (or similar products). My concern is that if I put down the Race Deck, the water will flow underneath and ultimately evaporate, but how do I clean out all the grit that goes under there with it? What horrible creatures will breed under there?

If I go with the slotted tiles, then I get dirt and sawdust under there directly. If I try to wash the surface, I still get a lot of water puddling underneath.

I'm thinking about fixing the slope... it can be an ugly fix as it won't be visible. I literally just want a better slope and I'm not sure what methods or products to use.

Suggestions?

The garage is 24x22, but soon to be about 30x22.

 

[roscoe2000]

It would be best to remedy the source of your water intrusion or put in a pit with sump pump. The standing water is safety hazard when using power tools and second is mold growth.

 

[JohnnieMo]

It would be best to remedy the source of your water intrusion or put in a pit with sump pump. The standing water is safety hazard when using power tools and second is mold growth.

The water intrusion are those pesky automobiles I drive around in the winter time.... not much I can do about them. There are no leaks.

 

[JohnnieMo]

Can anyone offer experience on how well the water evaporates once it gets under the Racedeck?

I'm looking at designs and I'd like to put a solid floor in the workshop area (the front of the garage) and then put the free flow tiles under the vehicles. I just want to get the right blend such that I get good drainage but without dirt and sawdust getting underneath where I don't want it.

Can anyone comment on how the free flow tires affect a wood working shop? Are they to be avoided?

Here is a rough idea of the layout.