Questions for the Concrete Guys!?

[button1833]

I have been reading through GJ flooring for the last couple of weeks and I still have some questions.
I am going to be putting up a 24x36 detached garage soon. I am in Northern Virginia and need to know what to ask the contractors to make sure I’m getting good concrete work done.

What is recommended vapor barrier and fill?

Where do all you Pros think the cuts should go? If any

My main concern is the finish and how level it is. As for the finish I like the smooth slab better than the brushed type. I often put cars on dollies and find them much easier to move around.

I will have a 4 post lift and work on some heavy cars. I also have some heavy equipment (lath, Mill). My biggest concern is it being level. I think the norm around here is ¼” over 10 feet. I will not have water ran to the building, so no drain.

I also have been reading horror stories from concrete dusting… How can I avoid this?

Thanks in advance to everyone. GJ is truly a wealth of knowledge.

 

[pauloman]

vapor barrier is usually just plastic to keep ground moisture from migrating through the concrete and causing problems.

If you ever want an epoxy floor finish a brushed top that has some profile is a better bonding surface than a polished smooth surface.

I would also look into in internal concrete sealer (one that leaves nothing on the surface) which are cheap and just sort of mopped on. This will prevent oils etc from penetrating below the surface which could cause serious coating problems (or prevent coating the surface) in the future. they can be applied before the concrete is fully cured (in fact better if they are)

 

[BECC]

Vapor barrier - we use 6 mil with taped seams for our slabs holds up better to wire mesh and pouring than 4 mil. VB is code for Florida with Radon gas and termites. For some industrial pours we use 10mil thickness, not necessary for your needs.

Fill, use clean fill under the vapor barrier, sand etc, no organics (roots, sticks sod) as it will decompose. 6" of rock is recommended for freeze thaw.

Cuts usually go on a 10ft x 20ft section max. for down here, maybe more up there.

Finish - if not outside or wet area, smoother the better. For dusting, avoid burning in portland when machine troweling as it usually provides a good finish but will dust up over time. Find a good finisher and you won't have any problems. Like pauloman said, a good concrete sealer will work well, talk with the supply house (not Lowes or HD) about what will work for coating it in the future if you plan on painting it. I wait 30 days min before i think about painting it gives the concrete time to breath out and cure.

Levelness, my 36x28 shop was level and slight slope towards the roll up door so i could wash and squeegee out the door opening when i cleaned it, worked great. first job as a mechanic at sears in HS was to clean the floors for a 22 bay shop.

I through in some extra rebar where my lift posts were going just because its cheap and works.

 

[button1833]

Levelness, my 36x28 shop was level and slight slope towards the roll up door so i could wash and squeegee out the door opening when i cleaned it, worked great. first job as a mechanic at sears in HS was to clean the floors for a 22 bay shop.

Mine will be 24w x 36 deep with one 10ft door on the 24 ft side. What would a "slight slope" be. It would be nice to have a slope to help sqeegee like you said, but I dont want a tool box rolling out of the shop!
Whats your suggestion?

 

[button1833]

I would also look into in internal concrete sealer (one that leaves nothing on the surface) which are cheap and just sort of mopped on. This will prevent oils etc from penetrating below the surface which could cause serious coating problems (or prevent coating the surface) in the future. they can be applied before the concrete is fully cured (in fact better if they are)

Thanks for the reply
Is there any one brand that comes to mind that is better than the norm. or are they all pretty basic and the same?
Thanks