hot tub base - low spot blues

Old 11-06-20, 07:11 AM
Thread Starter
Join Date: Feb 2014
Location: USA
Posts: 105
Received 2 Votes on 2 Posts
hot tub base - low spot blues

Hi all and thanks in advance for any input! I've recently poured a 10'x10' concrete slab in preparation for delivery of my very first hot tub next month. Unfortunately, the finished slab has a low spot which is just less than 1/4" at its deepest point. The two photos below show the area that I'm describing; one of the photos is a close-up of a 2x4 standing at the deepest point of the low spot. Importantly, I would note that the entire ~6-inch perimeter around the slab is just about perfectly level.
The question is whether this imperfection in the slab requires remedy, or if I'm dwelling on a non-issue. If it's a problem, how would you go about fixing it? Self-leveling concrete?
Thanks again.

the low spot is not really as large as the wet area in this photo.

that's a 2x4 standing in the deepest part of the low spot.
Old 11-06-20, 08:01 AM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 9,142
Received 873 Votes on 795 Posts
Hot tubs are supported around the perimeter so that is not an issue. My hot tub has a thick plastic base covering the bottom and that wraps up the sides about 3" up the sides so the low spot would not be an issue.

I think you need to confirm how your tub is constructed!
Old 11-06-20, 08:56 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 27,609
Received 1,443 Votes on 1,298 Posts
Look at the delivery prep packet for your spa or it's manual. It should describe where and how your spa needs to be supported. I suspect your 1/4" dip won't cause any problems but if that low area happens to be a support location for the spa you could put down a 1/4" thick aluminum plate or sheet of plastic. You could also use self leveling compound or a concrete topping mix to fill in the dip. But, I don't think it will be necessary. 1/4" isn't much and is probably better than most spa installations get.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: