Waterproof / Crack Repair in Concrete Floor Before Putting Raised Floor Over it Post your questions and get answers regarding all areas of drives, pathways and patios

[adamski]

Not sure if this is the correct sub-forum, please move it if it isn't!

I am about to build a raised floor on top of a concrete floor of a workshop building. The workshop looks like it was built in two stages. Where the second floor was joined to the first, next to an adjoining wall, there is a large crack where, in rare cases of heavy rain, the water will bubble up from outside and leak in.

There is another issue where the outer ground level has risen above the workshop floor level, and I plan to dig a trench along the wall and fill with stones/gravel to keep drainage below DPC level.

But the question I have come here to ask is how best to seal this crack/gap. I have found a product I think looks like it would do the job. Also looked into "resin injection" but that may be overkill and expensive.

Any tips/recommendations? Thanks

[B4Less]

Hi,

I would think the resin would work but it is hard to give a full a proper judgement by just reading your question.

Might be best to try the option you found first and see how that goes but to be sure your floor does not give any more issues I would steer down the road of resin. This way you know the job is done correctly.

Regards

[adamski]

The product I mentioned (the name and link were removed by a moderator) is basically a tanking/slurry mix. Going on some advice I found elsewhere, I'm going to try that first, along with waterproof cement to fill the gap. I will also apply the tanking to the outside area where water is getting in through the wall.

While I'm at it, I might apply it to the lower part of the walls which have signs of previous damp.

[B4Less]

Ye I think that would be best. Make sure the area is completely dry before trying any solution as if it is damp it will not perform correctly and you may end up redoing it.

Regards