I have a large (65 ft x 30 ft), old (36 yrs) concrete slab patio. It was constructed with 2x2 boards between slabs, but these have rotted out, and the gaps are filled with dirt (and weeds). I want to fill the gaps with something solid - I have been thinking about colored concrete - but am worried about expansion & contraction & subsequent cracking.
Originally posted by Joe66: I have a large (65 ft x 30 ft), old (36 yrs) concrete slab patio. It was constructed with 2x2 boards between slabs, but these have rotted out, and the gaps are filled with dirt (and weeds). I want to fill the gaps with something solid - I have been thinking about colored concrete - but am worried about expansion & contraction & subsequent cracking.
Using the colored concrete would be okay as long as you maintained some type of control joint which is what the 2x2 was for. You can get expansion joint material that is as thin as 1/4". So if you sandwiched the concrete between the expansion material you would have a 1" strip of concrete. From a design standpoint it may not be the most appealing visually but then again it could look quite good depending on the current color of your concrete. If it were my patio, I'd consider removing the weeds and planting a low ground cover that would hold up to foot traffic, this would soften the lines of the patio. Another option is to use colored or tinted mason's mortar mixed with sand and compacted into the joints and lightly sprayed with your water hose, the ratio should be approximately 1 portion of sand to 6 portions of mortar. This will yeild a weak form of mortar that as the patio expands and contracts the cracking will occur where the mortar and concrete meet and will be barely visible.
Posts: 63 | Location: Farmville, VA | Registered: 15 August 2005
I ended up removing the decayed 2 x 4 and dirt down to about 3" (the slab is 4").
I then used colored polymer concrete to fill the gaps. (Colored because I didn't think I could match 36-year-old concrete's color.) I did not use any material for expansion. I did this during the summer of 2005, and it has not cracked yet, but I AM watching...
Originally posted by build4you: Using the colored concrete would be okay as long as you maintained some type of control joint which is what the 2x2 was for. You can get expansion joint material that is as thin as 1/4". So if you sandwiched the concrete between the expansion material you would have a 1" strip of concrete. From a design standpoint it may not be the most appealing visually but then again it could look quite good depending on the current color of your concrete. If it were my patio, I'd consider removing the weeds and planting a low ground cover that would hold up to foot traffic, this would soften the lines of the patio. Another option is to use colored or tinted mason's mortar mixed with sand and compacted into the joints and lightly sprayed with your water hose, the ratio should be approximately 1 portion of sand to 6 portions of mortar. This will yeild a weak form of mortar that as the patio expands and contracts the cracking will occur where the mortar and concrete meet and will be barely visible.
Any advice on whether I could put blacktop over the concrete?
Blacktop makes a pretty lousy patio...when it gets warm, it softens, and things like furniture legs sink into it. And it's ugly.
Did you consider placing concrete interlocking pavers over the concrete? They're not perfect either, because of their irregular surface, but at least the look good and don;'t soften like blacktop.
Or else, why not remove the concrete, and replace it, doing it right this time?
Architect (NY) and Home Designer (PA)
Posts: 2559 | Location: Tobyhanna, PA | Registered: 24 October 2005
Originally posted by Richard Hetzel: Blacktop makes a pretty lousy patio...
**Oops. I meant to indicate that I'm talking about a driveway and do realize it's not as attractive but price is a consideration. Where I am, the cost of concrete is four times the cost of blacktop.
Did you consider placing concrete interlocking pavers over the concrete?
**Afraid I don't know what this means but will check with someone who does.
Or else, why not remove the concrete, and replace it, doing it right this time?
**I guess this means that removal is required for re-paving?
If you're talking about re-paving a concrete DRIVEWAY, then blacktop is OK. Make sure the concrete is clean, and ask the pavers if a bond coat or tack coat should be applied so that the blacktop adheres well to the concrete. Also, patch any serious cracks in the concrete with blacktop before installing the topping.
Architect (NY) and Home Designer (PA)
Posts: 2559 | Location: Tobyhanna, PA | Registered: 24 October 2005
Thanks for the tips. There are many cracks and surface holes in the concrete (and many weeds poking out of each one), so there needs to be some major preparation work.
I got a quote from the blacktop paver but am hesitant to put blacktop with a stone home. Will it look like an eyesore? In fact, thinking ahead to getting the concrete work done, will it be possible for these folks to pour some concrete around the foundation in several low spots?
