Garage Floor Overlay

[elminer]

I moved into a house 3 years ago that had a new garage with a wood floor and basement underneath. The floor is painted 3/4" plywood on 2x12 joists 12" OC. The joist span is about 13 feet. The previous owner had built the garage and had placed diamond plate over the plywood in the areas where the car wheels run.

Over the last three years, water has run off the cars from melting snow, and even though I try to vacuum it all up, it has started to delaminate some of the plywood, it has gotten under the diamond plate which is rusting badly.

I am looking for something to overlay onto the garage floor that is durable, light and relatively inexpensive. In a perfect world, I would like to slope the floor to the doors to drain the water.

I've thought about light weight concrete or a thin coat epoxy. I can slope the concrete, but the weight may be too much. The epoxy is light, but being liquid, can't really be sloped. It also is hard and thin. While the floor has no noticable spring to it, I'm also afraid of it cracking and ruining the watertight seal.

Does anyone have any suggestions?

Ed

 

[BryanStein]

GOod luck and I don't envy your situation.

Sorry no suggestions.

 

[boo1]

What is the span of the 2x12's?

 

[ivanlocke]

Are you replacing the existing plywood and can shim the new plywood to the desired slope and then apply water resistant coating?

 

[boo1]

A membrane ($$$) or a sloped light weight concrete ($) top coat appears to be a good solution.

 

[71corvette]

Here's an idea, although I don't know how practical it will be for you - How about adding a carring beam beneath the timber flooring, perhaps a wide flange section supported by lally columns at the ends (and maybe the center). This would cut your span length by half and greatly increase the capacity of the floor allowing you to place a thin concrete slab over the existing plywood. I think this would eliminate the need for lightweight concrete saving you some money (altough you would probably want to limit the aggregate size depending on slab depth).

One other thing that may be worth a mention, be sure that if you do place a new concrete slab you maintain adequate clearance from the top of floor to top of slab.

Good Luck!

 

[jgillikin]

Your best bet for overlay would be an epoxy material. Before you could apply the epoxy, you would have to blast the diamond plate removing any foreign contaminants such as rust, grease, etc. Also, you may want to replace the plywood with a treated grade of marine plywood. Use a mositure-tolerant epoxy primer prior to the application of the epoxy floor topping. The epoxy floor topping should have the adequate amount of filler to prevent shrinkage which will lead to cracks.

 

[boo1]

I would think, epoxies would crack in this application.

 

[ivanlocke]

Haven't you always wanted a linoleum garage?

 

[boo1]

That may work but enshure the seams are will sealed.

 

[snafuman]

There are a number of fillers which can be added to epoxy, the cheapest being a commerical grade of wood sanding dust. Chopped and milled fibers can also be added for strength, fumed silica for work-ability. Fillers are a good idea as they can add alot of thickness to your epoxy coat for a lot less money than by just making the coat with more epoxy, also you can thicken the epoxy with the filler to the consistency you want, and shape it to a certain extent. Having said this, epoxies are expensive and the quantity it could take to cover a garage floor, even with fillers, may cost you more than you are willing to spend. I would expect that the cost of building up your floor with epoxies to the point where it would drain as you want it to would require a prohibitive amount of material.