Damp Proofing Concrete Floor (workshop)?

[Paragon36]

Dear All,

Not CNC related I know but I need some advice.

I currently have a home workshop that has a number of machine living in it such as manual / CNC lathes and milling machines.

The workshop sits on a concrete base.
I visited the workshop after a few weeks of absence an found damp patches on the concrete floor at the edges a couple of the machines had some light service rust.

To be honest the floor is inadequate in its current form as it has not been treated or painted and as such the dry areas accumulate concrete dust.

What could I use to treat this floor for damp while sealing it.
Iv'e seen some epoxy based paints etc etc.

One thing I should point out is that the machinery that is located in the shop can only be raised and blocked while the floor is being treated as I do not have the facility to relocate the machinery. The blocked areas will be treated after the majority of the floor is completed.

Any advice would be greatly appreciated.

Kind Regards,
SRG
Location = UK

[RICHARD ZASTROW]

I sealed mine with two coats each of a product common in the USA, Thompson's Waterproof Sealer. I followed that with concrete floor enamel.

Since this was below grade, I sealed the walls also. A builder contractor friend of mine said that if it rained heavily, my building will pop out of the ground. LOL

Dick Z

[MyCattMaxx]

I used 2 part epoxy paint. White in my 40x40 section and gray in the machine shop.

[ViperTX]

If you have moisture coming up from the ground below, then most anything that you put on the surface of the concrete will eventually flake off.

Unless the moisture is from a high water table it is most likely seeping in from the edges of the concrete slab, so you need to move the moisture from the perimeter of the slab and create some type of moisture barrier on the outside of the foundation.

Paul

[MarcoBernardini]

I had a basement with a raw stone floor, pretty ugly, so I used these black things: http://commons.wikimedia.org/wiki/Fi...fabbricati.jpg below a 5 cm cement layer. They allow air to circulate under the floor and, being plastic (recycled!) they also prevent damp to climb up from the ground. They are also radon proof, for who is concerned about this.
Sorry, I don't know their English name

[Paragon36]

Thank You All for your replies.

My initial process is to dry out the damp areas of the floor while checking the perimeter of the base for problems as suggested.

I think then I'll go for an two part water based epoxy paint. Reds got my fancy!

Thanks Again,
SRG

[kling8]

Where is the dampness coming from? What is treating the floor going to do? I would find out what and where the leak is coming from, and fix it at the source.

[stevespo]

Run a dehumidifier for some time to help dry out your slab before applying a surface coat. Follow the epoxy directions and do whatever they suggest for cleaning and etching. Don't skip these steps, otherwise you won't get good adhesion and it will flake and peel off. I've been there.

In my own experience, I had dampness coming up through the slab, as well as through the wall/floor intersection. Once or twice a year, we would get a significant amount of rain and I would end up with 2-3" of standing water *everywhere*. Your problems don't sound nearly as drastic, but it's still a hard problem to solve.

I do like Marco's suggestion of the rubber mats with a subfloor on top. Our local home center sells them in 2x2' interlocking squares. You could even lay down 4mil plastic, do the rubber, then a plywood floor on top. That might last longer than a paint solution, but the paint is quicker and cheaper and may do enough for you.

My ultimate solution was to empty my basement, remove the old floor, excavate, pour new footings, install a proper perimeter drain with sump, 5" gravel, vapor barrier, and a new 5" slab. I also gained about 20" of ceiling height. This was quite drastic, and $$$, but has completely transformed my dank dungeon into an amazing work area. For my needs, it has been well worth it.

Steve

[MrWild]

I don't know about all that work (footings, flooring, excavation), but the proper way is to install a sump system around the periphery of the basement. A guy I worked with did his on his own. In the vein of if a little is good, a lot is better, he dug the sump trench well below his footing. Before he was done, a heavy rain came through and an entire wall collapsed. It cost a little bit more for all the repair work than he had estimated for his DIY sump system...

[Kevin Taylor]

Yes to the dehumidifer and on paint most concreat need's cleaned with muratic acid and water be for paint but watch out it makes thing's rust fast I had things with oil on them that tried to rust even in the summer with the door's open and the wind blowing through the shop I have seen tool shop's with wood block's on end like a brick street or patio they said it was nice to prevent damaging tool's if droped but looked like a fire hazerd and hard to sweep and keep clean Good luck Kevin

[stevespo]

My old slab took a lot of cleaning and the adhesion on the old, friable slab was not great. Definitely clean and etch which will help. A good 2 part epoxy may do the job. Please let us know how it goes.

On my big basement renovation, the masonry contractor was licensed, insured and experienced. The footings go down quite deep and then the perimeter drain was set in 5" of gravel, which sits above the bottom of the footings.

Everything had to pass city inspection, which is quite strict. The whole thing made me VERY nervous, but went off without incident. We sit at the bottom of a hill and once or twice a year, there is a little bit of water in the sump, but that is another 2' below the level of the floor.

I'm definitely NOT trying to brag about anything here, just thought people might be interested that this kind of thing is possible. I never thought it would be possible, or afforable - but it really worked. My house was built in 1875 with a New England "rubble" foundation.

Steve