Walkout basement: Pavers on a slab? - Contractor Talk - Professional Construction and Remodeling Forum

bert0168 · 08-09-2009, 12:42 PM

I am putting a walkout egress in an existing poured wall basement. The plans call for a slab at the base of the new steps with a drain tied into the sump and then day lighted. This is not the problem.

The archy has spec'ed paver stones to be placed on the slab to match the treads and patio at grade. In talking with my mason, we don't feel this is going to hold up to freeze/thaw. The pavers on the pato are only butt up to each other, not mortared in. If we did mortared in the well slab pavers and not the patio, it wouldn't look right any way.

Not to mention, if we don't provide a drain at the paver surface AND the slab surface, how would the water that goes through the pavers and sits on top of the slab drain?

My gut says not to put the pavers on the slab. Am I correct in my reasoning?

BreyerConstruct · 08-09-2009, 01:50 PM

Many paver systems won't extend high enough to work, wither.
Also, if they're the type to step back an inch every course, it gets big quick. Trust me, I learned!

I'd vote for standard block or maybe split-faced block for a decorative accent, but mortared in!

~Matt

bert0168 · 08-09-2009, 02:27 PM

Quote:

Originally Posted by BreyerConstruct

Many paver systems won't extend high enough to work, either.
Also, if they're the type to step back an inch every course, it gets big quick. Trust me, I learned!

I'd vote for standard block or maybe split-faced block for a decorative accent, but mortared in!

~Matt

Not sure what you mean.

I want to do a simple concrete slab w/ brush finish. That I know I won't have problems with.

This is what they want to use http://www.nitterhouse.com/masonry/p...ing_stones.php

I have some of the pavers. They are all the same thickness but look to be designed for no mortar joint.

concretemasonry · 08-09-2009, 02:29 PM

What kind of paver? - Interlocking concrete with no mortar and set on a 1" sand setting bed or clay brick set in mortar?

When you said mason contractor that poses a problem. Very few interlocking pavers are installed by mason contractors because they do not understand the principals since it is a totally different material with different proerties and instalation techniques.

bert0168 · 08-09-2009, 02:38 PM

It's not an interlocking system. They are laid on a compacted aggregate base system. The website says nothing about setting on a concrete base.

These things are essentially squares or rectangles that one lays in the pattern desired. Much like a brick walkway.

My mason sub, whom I have trusted for 7 years now, is only working the masonry portion of the job: excavation, cut thru the basement wall, footers, slab, CMU wall and stair set and then capping his work with the pavers selected. He isn't doing the patio.

I agree with him about the setting of these on the concrete slab. They won't stick thru the freeze thaw cycle. That is what I want clarification on. I have to go to the HO and want all my info to be correct.

This was a tough one to decide where it belonged, here or in Landscaping

ruskent · 08-09-2009, 03:16 PM

THose are not paving stones. THey don't have the right aspect ratio to be considered a paver. They are slabs. I see no proablem putting them on a concrete slab. Just install 1" of concrete sand on top of the concrete and then install these slabs. Your drain will be flush with the top of these slabs not the concrete.

bert0168 · 08-09-2009, 03:20 PM

Quote:

Originally Posted by ruskent

THose are not paving stones. THey don't have the right aspect ratio to be considered a paver. They are slabs. I see no proablem putting them on a concrete slab. Just install 1" of concrete sand on top of the concrete and then install these slabs. Your drain will be flush with the top of these slabs not the concrete.

OK but if the drain is on top of the slabs, and the slabs are say 2" thick with 1" sand, what happens to the 3" difference where the water sits below the drain entrance?

ruskent · 08-09-2009, 04:04 PM

Quote:

Originally Posted by bert0168

OK but if the drain is on top of the slabs, and the slabs are say 2" thick with 1" sand, what happens to the 3" difference where the water sits below the drain entrance?

Why would water go below the drain?

BreyerConstruct · 08-09-2009, 04:50 PM

Quote:

Originally Posted by bert0168

Not sure what you mean.

I want to do a simple concrete slab w/ brush finish. That I know I won't have problems with.

This is what they want to use http://www.nitterhouse.com/masonry/p...ing_stones.php

I have some of the pavers. They are all the same thickness but look to be designed for no mortar joint.

Sorry, my bad- I assumed that you meant using a interlocked wall / paver system.
Again, I mis-read & thought walls, not floor.
That looks like that would work but I'd want to make sure the drain height didn't trap water in...

~Matt

bert0168 · 08-09-2009, 05:22 PM

Quote:

Originally Posted by ruskent

Why would water go below the drain?

Because the slabs wouldn't be mortared in between, only laid tight.

There is no way water won't migrate between the slabs to the top of the concrete. If the top of the drain is at the SURFACE of the slabs and not the surface of the concrete (which would be 3" BELOW the surface of the slabs), whatever water water drains thru to the concrete won't get in the drain.

Anything that gets undre the slabs and freezes will lift them.

If I can drAw it, I'll post what I mean.

bert0168 · 08-09-2009, 05:24 PM

Quote:

Originally Posted by BreyerConstruct

Sorry, my bad- I assumed that you meant using a interlocked wall / paver system.
Again, I mis-read & thought walls, not floor.
That looks like that would work but I'd want to make sure the drain height didn't trap water in...

~Matt

That's what I'm getting at. I have no way of guaranteeing water won't sit under the slabs. In winter, BIG PROBLEM.

UNless I am missing something. I need to talk with the HO on Monday and wanted to know what I'm talking about here.

4th generation · 08-11-2009, 09:58 PM

Isn't there a detail on the drawings for it?

customST · 08-12-2009, 05:52 PM

tell your mason to make the slab fall in the way you want it to drain. make the slab perfectly flat. use high grade thin set or epoxy. set your pavers. sweep sand in the joints. crack open a beer and relax.