Building A New RV Garage Questions

[Dargeljohn]

Higher ceiling, add a set of stairs leading to a loft or landing that can double as storage and RV roof access.

[Ken Thompson]

Originally Posted by crazylegs

6" is too thin for rebar, you will cause the concrete to spall and/or break up prematurely. If you keep to 6" then use a wire mesh about 2" from the bottom. This will help keep the concrete together when it starts cracking.

For commercial driveways I have used 8" of concrete with no rebar or mesh. On fire station and ambulance driveways I have used an additional layer of wire mesh. Maybe a bit of overkill, but it is a huge inconvenience to have these accesses out of order.

I do commercial construction, and 6” concrete slab is more than adequate with rebar in it. All of the fancy coated rebar may be spec’d out for a government job where it’s not their money. By the time normal rebar is structurally degraded, you will be long gone. Rebar only needs to have 2” of concrete above it and 2” below it, that’s all. If you want to do 8” slab, great! It will be a big waste of money, but it could be a start for a runway to land jets on. For the weight you are putting on the slab, you could do a 4” slab with wire mesh, rebar, of fiber. I do agree on the drains, power, water, and sewer dump. A pit would really top it off as well.

[ben3rd]

I'd do floor heat (geo-thermal ) and air conditioner with the geo. I have several buildings for my business, collector cars and motorcycles with this. Works great and not very expensive to operate. 6" with rebar seems to work for me. Have very heavy equipment and no problems.

[cRViser]

typical slide up and over doors interfere with working on and around the roof. I prefer the style that roll up into the cylinder. This way they are out of the way and no headaches!

[tfialko]

Originally Posted by Capt Van

We have a 2022 DS 4369 on order so it looks like a new garage is on the horizon. I'm building a 30' x 70' x 16' with a 14' x 14' OHD.

First, does anyone know the weight of the coach? I'm going to go with a 6" slab with fiber, might also add rebar.

Looking for suggestions anything that you have or would have done.

Some of what I have planed so far

Insulation, LP heat, 20/30/50 amp service, sewer dump.

Here is a drawing of what it will be

https://photos.app.goo.gl/nZSgDAS1U5sgJqjPA

https://photos.app.goo.gl/1zPQoprccWgs89fN7

http://https://photos.app.goo.gl/dt4QeY3mGhhhQYhn7

This about what it will look like

https://photos.app.goo.gl/ZDaFSHReFm1wsrVe7

Thanks for any input.

Might think about 20' high ceiling with16' high door. The high ceiling gives ability to do roof work /repair when parked in garage and the high door throws light on ceiling.

[OneRVer]

Do not leave out the rebar. Fiberglass isn't enough.

[Quickuc]

Any plumbing at all? If so don't forget drainage in floors, skylites? By the way im very jealous!!

[JHinman]

5” or 6” thick slab is plenty.

Subgrade preparation is important, as is drainage of the subgrade. Moisture below the slab contributes to curl of the concrete.

Getting a low water/cement ratio will help with durability as well as minimizing initial shrinkage. Shrinkage and cracking is caused by water leaving the mix (concrete needs about 22% water to cement to complete the curing process, but concrete cannot be mixed or placed that dry.) Using less cement and less total water will give you good results.

Contractors like to add water to the mix to make placing it easier. They like to water the surface while finishing it, too. Both practices will reduce the durability of the floor.

Rebar in the floor helps to distribute cracks, so you get more and smaller cracks instead of fewer, larger cracks. That is generally a good thing. Rebar does nothing for the strength of the floor. Getting a low water/cement ratio, a good cure, and good control joints are more important than rebar.

If you live in an area where roads are salted for ice control, require 6% entrained air and either coat the rebar or leave the rebar out.

Epoxy coating the floor will help with cleaning and with lighting. If you don’t epoxy coat, at least seal the concrete.

I retired from structural engineering after 40 years. I have designed repair and rehabilitation of acres and acres of bridge decks and parking deck slabs. I could bore you for days on what works and why it works when it comes to concrete!

[Jincali]

I would recommend a 5k psi concrete and rebar 12” OC in the areas where the tires will rest when it’s parked. About a 5’ x5’ area for each tire. Spread out the weight over a large surface especially if the ground underneath isn’t compacted (I’m not talking about the gravel).
Placing rebar at 16 or 18 inch OC will not transfer enough of the tension stress in the concrete to it. This is fine for a walkway, patio, or light duty driveway. But not for a 50k lb MH.
Also, fiber only increases how much strain (bending) concrete can take before failing. It only provides minimal increase to its strength.
Don’t believe me look at how bad the expressways in Chicago are. Those are built using 12 to 18” slabs with 0000 rebar on 12” centers.

[gjh]

A little wider wouldn’t hurt mine is 16’ wide and I have to be perfectly center with coach to open basement doors fully open on both sides

[rw68RSConv]

So many posts - so apologies if duplicated info... but when I built my garage, my recommendations are:
1)Go with Radiant heat, not force air/lp. It is amazing as it heats up everything and a big -o-RV works as a giant heat sink to make it even more efficient. I heat a 1200sq ft shop for around $70 in the dead of winter. I went with twin electric heaters but looking at replacing them with on-demand inline heaters and dumping the tanks. It's a little more upfront but I will never build another without it, no clue how much I've saved over a standard furnace.
2) In KS, mine required footings below the frost line (36") by code. I had 4 36" square piers poured down to the virgin soil to support the floor. Again, a little more upfront, but 15 years later, there is not a single crack in the floor. (ok - one hair line)
3) Use a commercial door opener on side of door. Its a much cleaner install and mine have been absolutely trouble free.
4) floor is 6" thick, 6K concrete
5) rebar is 12" on center

Hope that helps.

[ronboatplane]

I just built mine with two opposing 14 X 14 doors. I pleasantly found my doors over the payment were indeed 14 foot clearance using roll up doors. I have a 40 foot version of the new DS and it needs about 13’ and 6 inches to be safe. Fortunately I have another 5 or 6 foot higher above when inside. The openers need to be set correctly so they do indeed allow proper clearance. The purple button medium duty openers are set by turning two mechanical knob so the micro switches for up and down are properly engaged. While yellow button openers are available for residence openers the purple button ones are all my builder could find for larger doors.

[baldwingolf]

Capt Van , Great Project. I would suggest a perimeter footing around the garage at least 16 inches deep and 12 inches wide with 2 # 4 rebar around the entire footing, I would also add a 6 inch curb around the entire exterior above grade to support the structure (walls & roof load) and keep the wood siding above grade. Note* except where you drive into the garage"s and any Man doors. Have the footing dug out the drive in doors at least 6 inches deeper than the exterior perimeter footing. You would also need anchor bolts around the perimeter( this is for uplift and laterial bracing) you can also run electrical and water conduits and sewer line perpendicular to the footing so they come up into the exterior wall and under the slab to where connections are. If the wood siding is 4'X8'sheathing that will act as Lateral Bracing.Slab rebar or wire matt.

[Mikenat]

My 2 cents are this. Do the drain for the ac units to drip. 6 inch with rebar is all you need. My barn is 50 x 28. 16 ft wall plate. Doors 14x 12 and a 8x10. 1 side access door. Lighting using led work lights up top. All hard wired 50 amp and 30 for 120v usage. Barm is insulated. Overall spent $57 k I live in my house up front.