garage floor , will it take paint

hi all

recently built garage floor, and in fairness to the guy that that did the floor he put a super finish on it with a power float, it was like glass, now i am concerned that it may not take the paint, will there be enough grip,, any one else painted a gargae floor lately,

i have seen kits in atlantic home care but they are kind of expensive too

I painted my garage floor last month. Luckly it was fairly rough, so there was no problem with adhesion. The tin of paint (can't remember the name but it was specific for garage/car showroom/floors) did say that if the floor was powerflowed or very smooth then it would have to be acid etched for the paint to adhere.

So you may have a bit of a job ahead of you.

You should get a lot on info from google.

Clonboy, now you've got me worried as I have the exact same situation, i.e. newly laid power floated concrete garage floor.

Did not realise the smooth finish was going to be a problem, I have already bought the International Garage floor paint and primer in B&Q ( fairly pricey), but waiting for the floor to dry out fully before doing anything.

How long are you waiting to let the floor dry out, Mine looks dry except on a damp day I see some moisture still rising in corners and around edges, apparently you need to wait about 6 months to let it fully dry and maybe longer in cold/damp climate.

Anyway interested to hear how you get on,

Mike

sorry Mike

i have just had it plastered internally, and looking into doors at the moment, its floated about 6 weks now, but still a bit messy after a the internal plastering.
the guy that power floated it was doing me a favour getting such a good finish and now i am a bit worried, it was too good

i will look into doors now and then try to get it closed up,, just dont want to waste a lot of money on paint that wont last in the long run

found this


Believe it or not, you'll get the stuff in Woodies, I've just done my own.

EpoxyShield - Garage Floor Paint
http://www.epoxyshield.com/CBGProduct.asp?pid=16

I was all over eBay and other places trying to find the stuff, and ended up getting it there. EUR99 for a kit which covers around 20-25sq/ft I think, depending on how pourous the concrete is - just gotta go easy on the flakes! I've a spare second kit - but used all the flakes ....

The majority of the work is in the prepartion, you need to get all the concrete dust off the floor and out of the air. Again this comes back to the finish on the floor, luckily mine was very flat and smooth as a result of about 8hrs power floating. The kit gives you an acid etch solution, but still requires a lot of scrubbing into the floor - plenty of elbow grease - and plenty of water to keep washing it out. The kit also comes with a video guide - which I thought was a bit of a joke, but actually gave some good tips.

If it's a fresh floor it'll need to be down a good 4 weeks to allow the concrete to settle, also needs to be dry - I had dehumidifiers in there for 2 weeks pulling water out of the floor and air in general. The washing from the etching also causes a problem, so need to get as much of that water out and off the floor.

then i was wondering could i buy hydro chloric acid myself anywhere to etch the floor??/

There is a product out there called ESP (Easy Surface prep) which can be put on all surfaces including glass before painting. Im sure it would suit smooth concrete as well. see [broken link removed]

its advertised as being for non pourous material

would concrete be classed as a pourous material?

I will probably just do a good hoover / clean of the floor and try a test area to see how the sealer/paint takes. I might wait until about January , my floor will be down 6 months by then do I am hopping pretty much naturally dried out.

Will let you know how it goes

Generally, 28 days should be enough drying time for a fresh concrete floor before overcoating it. A way to check would be to stick down sellotape in different areas around the floor and leave it overnight. If the underneath of the sellotape is damp the following morning, then it is still not cured enough to paint.
If it is cured off enough, you will need to roughen up the surface only if it is a glass like finish. I generally wouldnt recommend acid etching due to smell, disposal of acid after, etc. For a large area, you can hire a floor sander from a tool hire shop and lightly abrade the surface. these generally come with a hoover attachment so shouldnt be too dusty. For a small area, a hand held grinder with a wire brush attachment should do the trick. Its just a light abrasion you need that will feel slightlly rough on your fingertips. Once you have prepared the floor like this, you can hoover up the remaining dust and apply the paint as per the instructions.

mmm, think ill try to sand it a little

to mike, one point, if you do one area and its ok fair enough, but what if it actually takes maybe 6 weeks before it starts to peel,

thebishop:

I should qualify, that I went for a spec maybe not necessary for a detached garage and have a radon barrier under floor (not planning any change of use but the logic was go for standard housing spec as the extra cost at construction stage is minimal).

This of course means the floor is sealed underneath and prolongs drying times, If your floor is not sealed drying time maybe faster, though God knows with the summer we just had its doubtful.

Heres a good link on the subject:
[broken link removed]

I knowfro my florr the sellotape test is not even necessary yet ( at 4 months) as there are obvious damp patches on the floor edges on humid days, though gradually improving.

Clonboy: good point, I think thebishops advice to go with a light abrasion might work, acid etching sounds like overkill.

Mike

RSMike,

I'm not sure where that link is getting 4 months to a year but the standard practice in industry in Europe is 28 days curing time for freshly poured concrete before overcoating. Generally if the floor is showing patches of mild dampness, then it should be ok to overcoat as nearly all floor paints will allow water vapour molecules to pass through without damaging the coating. If you dry the damp patches with a gas bottle / blow torch that would do it.

The standard drying time for a concrete floor is 1mm/day for a rough finished floor.28 days refers to the time when concrete achieves its design strength.
When a floor is power floated it slows down the escape of water from the concrete mix.Therefore you would have to allow extra time for a finished floor to dry completely.The drying time commences from when the floor is protected from the elements.Concrete is porous so will absorb moisture if available.The

use of dehumidifiers would speed up this process considerably but can be harmful to your build.A wet vac might be a better solution.If in doubt check the moisture content of the concrete with a moisture meter.

wexford dude said:

The standard drying time for a concrete floor is 1mm/day for a rough finished floor.28 days refers to the time when concrete achieves its design strength.

Click to expand...

This seems to tally with what I am reading in my trusted Collins DIY manual

"Floor will not fully dry for about six months, allow a month for every 25mm (1 inch) of thickness"

If you do a bit of googling a few internet articles say the 1 inch per month rule is only up to 50mm after that you have to wait longer, one quote from a book on dampness in buildings says that for 150mm of concrete, drying from one face, a year is required to fully dry out.

My builder who's been in the business for 35 years is also telling me, to allow at least 6 months before putiing down any flooring or sealing, ( he says tiles are ok to go down sooner).

I also think the 28 day is the concrete curing time , not the drying time.

update.. i cleaned it , well swept and hooverd it, thenpainted it with the paint from woodies, 45 euro a can. looks great so far and no complaints even though iut was smooth

Hows it now?
Just got a steel shed, with condensation roof, and got it ply lined. Some job. Floor was power floated and looks like glass! Anyhow, i'll leave it for 6 months before putting sealant on it, and then will tackle the painting. Interested in comments about putting paint down directly or epoxy, sanding etc to roughen up prior to painting.

6 months later , still looks good, little dusty and not very shiny, but have been in and out alot latley as we are doing the lawns.

id really like to go adn give one more quick coat, actually, when i can