Making a Garage Pit Watertight Post your questions and get answers regarding all areas of drives, pathways and patios

[Jintynut]

I put a pit into my garage, under construction I ran out of concrete it wasn't possible to calculate properly due large boulders in the clay which had to come out, I returned to it a couple days later to complete. However due to high water table outside, as high as the floor surface, rainwater comes in under the floor and through the pit wall where the concrete was later infilled. I've to cut it and redo it but the same problem will reoccur, is there a solution which will fill or grout old to new concrete making it watertight.

Bert

[stoneyboy]

Hi jintynut,
Short answer is no.
You could try waterproof radio setting mortar, this may reduce water ingress but won’t stop it.
Regards S

[Jintynut]

I was hoping to coat the old surface with something like latex or a bituminous product and while it's still wet pour in concrete.

Bert

[stoneyboy]

Hi jintynut,
If you are going to try to tank the pit while there is still damp it will not be successful. Latex and bituminous products tend to be water based so will not dry and if you try to apply cement when they have not cured, the coating will “float” to the surface of the cement.
Regards S

[Jintynut]

Thank you Stoneyboy, If the latex or bituminous were allowed to cure or just before either go off the concrete is poured will that seal, the pit walls and floor were constructed using a waterproofing additive, the water-table drops quickly during dry weather.

Bert

[stoneyboy]

Hi jintynut,
Suggest you try your proposal and see what happens. Whichever coating you use it will not seal anything larger than hairline cracks. Bigger cracks should be filled before you apply the coating.
Regards S