I'm new here, let explain my situation. I have a 10X20 concrete patio. A 10X10 section is tied into the house foundation, while the other 10X10 section is tied into the previous section and not into the house foundation. This section has settled about 1" near the house and now it has a crack. I live in northern IL. and want to know if I can place #15 roofing felt over the concrete, then place sand over the felt, then place the brick down???? Will moisture/freeze thaw cycles displace the bricks or is it better to remove all the concrete? Not sure what to do, recomendations PLEASE.

 

As a general rule, anything you lay over a failing substrate will fail as well.

 

The concrete patio has been there for 15 years now and only the portion which isn't tied into the foundation wall has settled. Overall it's in good shape. Not sure if 1" of settling, and a top coat layer of sand will transfer to the brick??

 

What's the purpose of the felt? The sand certainly isn't going to filter through the concrete.

I would be a lot more concerned that a portion of the patio is now sloping toward the house as you stated it has "settled". This is going to allow rainwater and snow melt in along the foundation wall and cause numerous problems.

I would look into cutting out the settled section of the concrete. compact the area properly and just replacing the concrete in this area.

 

I thought the felt would serve as some type of moisture barrier between the sand and concrete, to prevent water from seeping into a fine crack.

Is it OK to lay the brick on the "good" concrete?? Is there any concern fo the freeze thaw cycles?? My thought on this is if water seeps between the pavers and gets trapped , freezes, will this cause the pavers to displace sideways or upward?

 

Anytime you have relatively solid impervious material as a base you must take precautions when laying pavers.

You recognize the problems of trapping moisture and frost problems.

There is on other thing to consider. -
Water can accumulate in the sand under the pavers if there is no way for it to exit down (through the slab) or out the side. If you have edge restraints, this can prevent the sand from draining the excess moisture. The excess moisture can cause the pavers to "swim".

Considering the cracked slab that slopes toward the house, I would have the small patio ripped out and replaced with a completely new, bigger paver surface. It will be much better to do it right.

Dick

 

"Considering the cracked slab that slopes toward the house, I would have the small patio ripped out and replaced with a completely new, bigger paver surface. It will be much better to do it right". Dick

Well sounds like I should just break apart the entire 10X20 patio and start from scratch. I thought I could avoid doing this, trying to avoid the additional time, and money.

What about adherring the pavers directly to the 10X10 half that did not settle or crack. Break out the other half and use ca6 mix for the base etc. for the other 10X10 half??

 

This is what I would do for myself, though it is not what I would recommend if I were doing it for someone else:

Level the slabs using a decent repair mortar that is capable of feathering. Mortar the pavers to the old slabs, considering the height at any doorways. If that was critical, I would use thinset, if I had 1/2 to 3/4 inch to play with, regular type S mortar. Fill joints with polymeric sand. Hope for the best.

If I was contracted to to the project, I would rip out all of the existing and do it correctly.

Understand that the concept of a flexible pavement is that it is both interlocking and flexible. What you want to do is not within the design parameters of the material from a liability standpoint, though it will probably be fine for years to come.

Edit-the above is assuming you mean concrete pavers, not clay brick.

 

[QUOTE=Tscarborough;1208109]This is what I would do for myself, though it is not what I would recommend if I were doing it for someone else:

Level the slabs using a decent repair mortar that is capable of feathering. Mortar the pavers to the old slabs, considering the height at any doorways. If that was critical, I would use thinset, if I had 1/2 to 3/4 inch to play with, regular type S mortar. Fill joints with polymeric sand. Hope for the best.

If I was contracted to to the project, I would rip out all of the existing and do it correctly.

Understand that the concept of a flexible pavement is that it is both interlocking and flexible. What you want to do is not within the design parameters of the material from a liability standpoint, though it will probably be fine for years to come.

Thats exactly what a friend had done, plus used a conventional base to expand the patio. Though it has not gone thru one winter yet, guess I'm being more conservative in my approach.