Mason/construction question

[Gregg]

Gentlemen, I have a couple of questions regarding an upcoming project and hope there are some knowledgeable forum members. My driveway is extremely long (approx 440 feet) and needs to be paved with asphalt (blacktop). Presently there is a base of "item 4". Prices to pave the driveway are in the vicinity of a new RCR!! As such, I am only doing this once. Plan was also to add an extension to the house, but based upon the current economic climate, we shall see.

1. The Mrs. would like the driveway to be bordered by Belgian blocks (cobblestones). How deep do they have to dig and what type of footing do the blocks need to be set in?

2. Is there any danger to pouring concrete in the winter?

3. Best season to pour concrete? I might pour a foundation and slab now for my extension and build when finances allow. It will be a garage floor with 4 post lift.

4. I need to grade the driveway. How deep does the base coat have to be?

Thanks. Gregg

 

[Cliff Beer]

Hi Gregg,

I might be able to help with some of this as I just went through a similar process with my own driveway....

1. The cobblestones can be set over compacted sand or concrete - either is fine. The important point is that there must be a border retainer to contain the bricks in place otherwise they'll walk all over the place. Four inch angle iron set on 12 inch spikes works well where using sand as a base, or, use concrete bolts to secure the angle iron if using concrete as a base. I'm sure there are other ways to do as well.

2. It used to be that you absolutely couldn't pour concrete where the ambient temp might go below freezing - you'd end up with cracked and weakened concrete. The concrete formulas these days can be mixed with low temps in mind and the freezing issue is minimized. If you're ambient temp is 30+ degrees you're just fine - the concrete laying on the ground will pick up a little heat from the ground underneath and put out a little heat from the curing process. I wouldn't pour in 10 degrees and falling snow however - that'll be a problem.

3. Spring and fall are good seasons to pour as winter has the potential freezing issue in 2. above and summer heat can cause the concrete to cure too quickly (also causing cracking). Temps are usually more moderate in spring and fall. Subcontractor pricing is usually better in the colder months as the subs are usually not as busy.

4. Not sure what you mean here. If you have to grade the driveway to make it level that's not a big deal other than the cost if you're using asphalt. If you're pouring a concrete driveway the issue is that the grading stirs up the sub-surface and even with compacting you'll end up with some settling, which then shows up as cracks in a year or two (control joints are created to help control this).

Hope that helps a little. I've definitely learned a lot with my own construction projects over the years - some painful lessons too.