Transition from Concrete Slab

[Granite]

Plan is to enlarge a patio without removing the existing concrete slab (exposed aggregate if that matters). New patio will be large pavers/slabs (such as Unilock Yorkstone). Can anyone offer some advise on the transition from concrete slab to the new area? I do not want to pour concrete to match the existing slab. I want to install a std. compacted aggregate base but then do I install 1" of sand? or is it better to install the slabs on dry pack? or? I know someone out there has done this . . . please send some ideas. Thanks.

[Paver]

Just dig out the soil around the slab for the extension and put in base material. Compact the base as you normally would, with the final grade even with the top of the slab. Yes, install 1" of bedding sand. Keep in mind, if you are in a freeze/thaw area that the base extension will move differently than the concrete slab in the winter. If the slab has cracks in it, consider covering it with a filter fabric to prevent loss of bedding sand.

[Granite]

The concrete slab is above grade . . . what would you use to keep the sand from washing out on a side where the patio will not be extended? Note: the side that will not be extended drops off rapidly; it's a steep slope of boulders and rock. It's not possible to add more boulders. Thanks.

[Paver]

You can use edging. Attach it to the concrete using anchors and then use regular spikes for the base extension.

[sandman]

http://www.pavetech.com/paveedge/segment3.htm

Overlays are becoming really popular. Try this method when overlaying and or adding on to an existing pavement,

[Granite]

You can use edging. Attach it to the concrete using anchors and then use regular spikes for the base extension.

Project was put off last year...may go this year. Regarding use of edging anchored to the concrete slab - that won't work; I can't give up any space, not even a couple inches, along that edge. Anyone have another suggestion? I was thinking of using a steel edge anchored to the vertical side of the slab. I'll try to send a photo(s) of the area later. Thanks.

[Paver]

Keep in mind that the steel will rust over time and possibly stain the outside pavers. Also, if you go ahead with this plan, you should run a bead of adhesive or caulk along where the concrete slab meets the steel to keep bedding sand from getting out.

[teacher]

If edging will not work because you cannot give up the space, and you don't want to deal with the problems that may arrive from steel edging (rust, loss of sand), another option may be using a mortar bed to mortar set the soldier course to the existing concrete slab. This route has its own host of problems if you are in severe freeze thaw climates (cracking), but it will lock in your pavement and sand will not escape. Trowel a consistent 1" thick bed of Type S mortar (3 parts type S cement, 1 part masonry sand) and set pavers level using a string line and compressing each paver 1/4" into the mortar bed. A latex additive can be added to the mortar to protect you a little bit more from cracking. PVC edging is certainly your best bet, but mortar set is another option. At the very least it's good to know your options.

[mrhodus]

Project was put off last year...may go this year. Regarding use of edging anchored to the concrete slab - that won't work; I can't give up any space, not even a couple inches, along that edge. Anyone have another suggestion? I was thinking of using a steel edge anchored to the vertical side of the slab. I'll try to send a photo(s) of the area later. Thanks.

If you cant give up any room on the edges of the concrete, use aluminum edging like the edging on this site http://www.surelocedging.com/paverrestraintedging.asp.
Install the edging so that the spike holes are under the pavers. You will have to install the edging first. Use a Hilti gun to fasten the edging to the concrete. This will allow you to place the pavers on the edge of the concrete and contain the sand.

[teacher]

While the aluminum edging you suggested will certainly work and will not give up any needed space, there are a few things you should be wary of. The space that you gain will be essentially created by giving up the back support of the edge restraint, which is what gives much of the edge restraint its strength. This will create a weeker system that will stand up to less load. You may see a higher degree of deformation along the edge of the pavement. If you are subjecting this area to high loads, i.e. vehicular traffic, I would not go this route.

[Granite]

Thanks for all the help and suggestions everyone...after thinking it over, I ended up tearing out the slab. I determined that I was going to cost myself more headaches than it was worth just to save the trouble of the slab removal. Sometimes you just need to get away from a project to clear up your thinking - know what I mean?

[Whyzman]

On yeah...happens to me all the times with crossword puzzles.. ;)