Garage Floor Painting (Damp)

[Joker7]

I want to paint my garage floor - I use the garage to work on my bikes. The floor show signs of damp ,if I roll back the bits of carpets the bike stand on.

I don't want to spend to much on it as it's only a workshop/store for my bikes.

Thinking if I paint it with a bitumen paint first and then a couple of coats of screwfix basic floor paint, would this work?

[Old_Geezer]

I suspect that depends on what you are hoping to achieve, and whether the damp is penetrating from below or dropping from above.

[Joker7]

The damp is coming from the floor, not loads - if uncovered to the air no signs of it, as I say I have a rubber mat one of the bikes stands on, if you roll that back you can see a damp patch.

[Clanad]

Could be wrong, but if the rubber mat you describe is solid... no ventilation... then the damp spot is likely only moisture collecting due to the coolness of the concrete and the relative warmth of the mat causing condensation. Especially if it disappears after removeing th emat.

Make sure your floor is clean of any oil or other chemical spots and thoroughly cleaned. Any good value acrylic cement paint will last quit a while, espcially since there won't be any direct foot traffic.

You could go to the expense and trouble of applying concrete epoxy paint, but that requires mixing as well as etching with citrus acid for adherence. Well worth the trouble since it will last forever.

[BRIGHT SPARK]

Joker...you will need to vent the floor for a few weeks until all signs of damp have gone..try a de-humidifier for a few days.If you paint over the damp it will peel off when you walk on it.

[The Builder]

As the others have said, it's usual to dry a surface completely for painting with traditional finishes. There is an alternative though. "Polybond Q19" is an epoxy 2-pack paint that can act both as a damp-proof membrane and a decorative finish...

http://www.acronpaints.co.uk/cgi-bin/polybond/htmlsheets/Q19Colour

Also... "Vandex" tanking slurry (from builders' merchants) applied to damp surfaces.. finished with floor paint.

You could even try "Parlour paint" (from Farmers' merchants) as used in damp milking parlours.

[Joker7]

Cheers Guys a lot of food for thought here ...