Epoxy garage floor prep can I have a bit of help please?

[Julian Thompson]

I’ve ordered some two pack epoxy and primer for my garage floor.

The concrete slab is 7 months old and was finished using a simple hand float on a pole from one of these bulk suppliers. It’s fairly flat but not what you would describe as “very smooth” - see pic.

Now, the supplier of the epoxy has told me to hire a surface floor grinder to “open the pores” of the concrete before I paint it.

I can’t find anyone locally with such a machine and I’m wondering if this procedure will actually achieve anything that a careful hoovering of the floor will not. However, given that I know precisely nothing about painting garage floors and the composition of concrete I’m turning to PH for help from those of you with more knowledge.

Would really appreciate some guidance.

[ColinM50]

Watching this with interest. My garage floor is c30 years old and a bit rough and crap so would love to do the same.

Products and price recommendations anybody?

[Jonesy23]

I know there's a few tools you can go with to level it like https://www.hss.com/hire/p/htc-gl270-grinder or https://www.hss.com/hire/p/floor-scarifier-110v. Dust removal needs handling too.

Don't you use something like an acid wash to key the surface?

I looked at this a while back and ended up using porcelain instead!

[divetheworld]

I am no expert on flooring, but there are some simple things to remember.
Oil and grease are the enemy of all adhesives. You need the floor to be clean for the adhesive to key on to.
Grinding the floor makes a flat surface and ensures a clean surface with a good key.

http://allgaragefloors.com/grinding-versus-acid-et...

I've put down plenty of resin floor coatings without grinding and had no issues, that's not to say that will be the case for you.

A bit North of you, but close enough.
http://www.hodgsontoolhire.co.uk/hire/building-sit...

[Getragdogleg]

we used an acid that made the concrete fizz a bit, then when it dried off we painted it with a two pack epoxy grey paint, that was 7 years ago and although thin where the lorrys go it held up very well.

Coovar made the paint we used.

[bogie]

I used 2 pack epoxy just fine on a fairly new concrete floor, probably 2 weeks, just float finished. With 2-3 coats of thick epoxy it does take quite a bit of the roughness out of the concrete and dries smooth

[Julian Thompson]

Thank you for that - I’m thinking that I’ll hoover it well, use their supplied primer and just paint it. If nothing else I really don’t relish the prospect of the dust created by grinding it - sounds horrific!

I’ll perhaps report back to this thread with progress during the job and after for reference in case it helps anyone.

[Andehh]

This is the something I plan to do this summer, bit will probably need to hire a machine due to they several layers of poor painting attempts.

Would be very grateful for a write up & pictures on h you get on & where you bought the paint from!

[jas xjr]

Would going over it with a needle gun help?

[Julian Thompson]

I’m not sure - but it’s over 100 square meters so it’s probably too much to do with a needle gun? I’m also concerned about exposing the aggregate a lot and making it worse? It’s all experiments really but I’m gonna give it a go. Materials arrive Tuesday.

I’ll take plenty of pics and report back.....

[Julian Thompson]

Ps one thing I forgot to mention is that for enough stuff to do two coats it was £900 inc vat including rollers and the primer stuff. So that is less than £10 a meter inc vat. When I enquired about the price of the job “done” they said about £40 a square meter inc vat - now I like to pay people properly for what they know and for a quality job but that went right over my pain threshold - that’s a tonne of cash for what is essentially painting a floor - or so it seems sat here right now!

[Andehh]

Thanks very much mate!

Who did you buy with our of curiosity? I only have around 30sqm, and have been budgeting around £200-250 so I am not a million miles off by the looks of it.

[Active75]

Hi OP,

I had an Epoxy company in Australia for several years. We used Parchem and Sika products, both have good data and application spec available online. www.parchem.com.au

What most on here are saying is correct. Really you only need to grind the floor to remove imperfections, or previous coatings etc if you have that issue. Then holes or damage repaired, again only if necessary.

Acid wash is good for keying some dirty floors, and thats only a light dilution. However as you have a new floor, you only really need to vacuum well to remove any dust, then mask up any areas you dont want touched. Apply the primer supplied, wait the required drying time then apply your epoxy.

It is very important to mix and apply exactly as stated in the instructions. Also to finish the complete job in one go. Make sure you have suitable rollers and strong paint poles. The best rollers use metal brackets with the roller attached at either end of the bracket. Whatever you use apply a steady pressure.

Remember your epoxy coat is only 2-3mm thick and will not hide small ridges and imperfections in the earlier float process.

Gloves, and good boots too.

It will be fine!

[Getragdogleg]

If you have any patches of new concrete that have that "fat" for want of a better word than you need to get that gone before you prime or paint.

By Fat I mean that thin layer or patch of watery dried out thin concrete that sits on top of the strong concrete that chips and cracks easily, its the watery fatty scum that sits on top when floating it off that has dried rather than being swept off at the point the concrete was almost hard.

[MellowshipSlinky]

‘Fat’ = laitance

[Getragdogleg]

MellowshipSlinky said:

‘Fat’ = laitance

thanks, at least someone out there could decode what I wrote !

[Julian Thompson]

That’s brilliant - thanks guys - I know exactly what you mean about the “fat” - I think there might be a few little bits of that here and there so I think our friend with the nail gun might be on the money for those bits...

In terms of supplier I can’t remember the name this evening - I’ll get back to you on it when I’m at the office.

[Julian Thompson]

So this is what you get for your £900 or so - the firm
I’ve used is “resincoat”.

To me (and I’m a total novice) there doesn’t look like anywhere near enough stuff here to do the job (105 square meters) but the guys at Resincoat assure me otherwise.

The 2.5 litre tins are primer and the 5 litre tins are epoxy. The silver tins are activator for the epoxy. Bear in mind I’m expected to do two coats of epoxy. Personally I don’t think we have a prayer of covering it?

Edited by Julian Thompson on Wednesday 14th March 22:19

[MellowshipSlinky]

Normally, printed on the label there should be coverage per m2 per litre.

[Julian Thompson]

Negative in this case. I’m relying on the manufacturer.

I just remember painting garage floors of an “ordinary” size with that red floor paint. You know the stuff from b and q or wherever. It comes in 25 litre drums and you still need two of them! In this case I’ve got this mahooosive floor and a sum total of about 110 litres of liquid which effective has to coat the floor three times. It might work - but we are talking roughly about 1 litre of liquid doing three coats on a concrete floor?