We’re tidying up our old very original garage, with the last big job being replacing the garage carpet the previous owners installed. The problem is the concrete is well and truly ‘original’: it’s not only uneven but also clearly has an issue with rising dampness (see photos below).

The next problem is that the first quote we’ve had back is for over $3k, given not only do they need to grind and feather the concrete, but also apply something called Uzin PE460.

We don’t think it’s worth spending that much, given the age/use of the garage, but would still like to improve it to the point we can replace the carpet ourselves (noting the current carpet is not fixed, we’d probably do the same). So I’d really appreciate some advice on a few key things:

1. What is a cost-effective way to deal with the dampness? Our builder has recommended Sika Blackseal Plus, which is a brush/roll-on waterproof membrane - will this work ok? Other products you would recommend? It doesn’t need to be perfect, but just a decent amount better than it is now. 

2. We’re not planning on getting it ground, given we’re not going to be gluing the carpet down; rather, we plan to scrub and clean it before applying any seal. Will that be adequate?

3. What’s the best way to reduce water ingress and protect the carpet at the entrance? (This is where it’s worn the most, both as a result of it’s where the car tyres first make contact and being closest to the door.)

Thanks for any tips and advice.