Sealing Concrete.

[Tandum (Robin)]

It stopped raining today after about a week or more and I've opened the obs to find the floor is wet. It appears water is being drawn into the obs via the concrete floor. Nothing else shows any sign of a leak so it's probably capillary, through the concrete. If fact around the pier footing you can see where water has been drawn in, between the floor and the rubber jointing around the pier footing, so it's also coming up from underneath.

I have installed that rubber flooring with the holes in it to soften the blow on dropped parts, but the holes catch any dirt and the dirt has started to turn to mold in some spots. So, I've pulled the rubber out, vacuumed and scrubbed the concrete floor and am looking to seal it better.

Unfortunately I can't lift the bottom ring which is sitting on the concrete to seal under it but I figure plenty of paint might keep the water from coming in and growing mushrooms

As I have lashings of acrylic paint on hand, will that be ok to use to seal the concrete or is there something special about acrylic concrete paint?

[mswhin63 (Malcolm)]

Try Bondcrete - http://www.bondall.com/bondcrete/Bondall_Bondcrete.html

Should be used on all concrete installations.

[Tandum (Robin)]

Cheers, I think there's a tin of it in the shed somewhere. It's 1part bondcrete to 4parts water + 24hours to dry then paint as I remember.

[ZeroID (Brent)]

Are you able to seal around the outside edge on the Ob to the concrete ?
I used a Bitumastic based sealer (lasts heaps longer than silicon outside) on a glass house sun room attached to a house. The stuff was water based and just painted on as a thickish paste then the surface dried to a film but it stayed flexible and as far as I know is still there after 10 years plus.
Paving paint for inside after that. Oil based so it resists better but needs to be dry surface.

[Tandum (Robin)]

Can you paint colour over Bitumen paint? Might worth putting that over the external concrete and the wooden bottom ring. I've still got about 10litres of acrylic here so will probably use that on the floor inside. It will have the rubber matting stuff on top of it anyway.

[cristian abarca]

the Acrylic paint will seal the concrete but it wont stop the water coming through. All that will happen is that a buble of water will form until the bubble pops. Water proofing paint might do it but there is a product that builders use to seal concrete before they glue floor boards on this will probably do the trick but it is expensive and smelly. Its thinner based. I cant recall what its called but I think Bostik make it.

Regards Cristian

[Tandum (Robin)]

Too late Cristian, I got the concrete sealed with bondcrete yesterday and slopped some bitumen paint around the outside to reseal the bottom wood ring to the concrete today, why not. Had to make hay while the sun shined

It has just started raining again so we'll soon see if that quick fix has done any good in a day or 2. I think it's going to rain forever

[ZeroID (Brent)]

You can normally paint the Bitumastic with an oil based paint. I don't think it likes Acrylic. The Bitumastic will develop a skin over a week or two but I wouldn't paint for at least a month when it feels quite firm.

[stardust steve (Steve)]

Hi everyone. There is also a product available called Gripset. Easy to work with, premixed and works well. It mat also be available in a range of colours, not sure about that though. I have a 20L tub at home, i use to constantly, UV rated too. Hope this helps ya

[leon]

You may have an ongoing problem, water is a bugger and can get in anywhere, probably a water resistant material should have been used first under the concrete to stop this happening.

I personally wouldn't put any paint or other substance on it until completely dry, and then you may get lucky, sorry but that is the fact of water seepage.

Leon

[2stroke (Jay)]

What you want to do is dig a trench around your ob slab, fill the bottom with crash rock, lay some sloted drain pipe and run it off to a storm drain, cover sloted drain tube with more crashed rock and then soil. Then for sealing wait till the slab is fully dried, mix the frisrt coat 1 3rd sealer and 2 parts solvent and put it on thick, if the slab is old acid etch it before sealing but this should be done any way as it opens up the concreate's pours for deep sealer penetration. Next coat add some glass beeds or anti slip to the final coat undiluted and your good to go

As I have lashings of acrylic paint on hand, will that be ok to use to seal the concrete or is there something special about acrylic concrete paint?

Umm yes there is lol, one seals and the one you have is a paint which will make it look nice but thats it.