Man door-floating slab question

[JayCat]

Building a pole barn. Poles set deep below frost line. Concrete floor/slab will be inside and "float" to allow for some movement if it needs to. Expansion material is attached around poles to keep floor from binding against poles along with natural shrinkage.

The 36" steel man door has a pole below frost line on either side to frame door. The question is what happens under the door where the slab is? Since the door will be attached to the poles it won't get heaved by frost. What about the part of the slab below the door? Could the concrete raise up and jam the door from opening?

JayCat

 

[hawkeye08]

What happens to mine is floor raises up under the door and jams it. I put an outside handle on the big rollup door so I could get in and out when the man door is jammed.

I put a 6x6 slab in front of the man door hoping to keep the floor from raising under the door. It helped a bit, but then slab came up enough to block the door. The last thing we did was to lower the slab 4" and make the door so it will "float" up a bit in the framing. Not happy with it yet... We have lots of clay and with the water running of the roof, it holds it in and when it freezes, we get a bit of ground heave.

If I were to do it all over, I might consider putting a short foundation wall under the door down below frostline (42" with footing). Another option is to put drain pipe in and try and reduce the water around that area (dirt doesn't expand, its the water that does).

 

[Willl]

Pour a separate threshold w/ some type of foundation.

Mine rubs a little harder then it did new but not bad.

 

[crusty 1]

I've done a fair amount of building and the frost heave issue is one that thier is no perfect answer to.I have found through trial and air that if you back fill holes with pea gravel and no dirt seems to work best.I believe the small stone acts more like a bearing and has a hard time [grabing on to lift].I've also found that after the first year the problem gets less.The more you drive in and out the deeper the frost is driven into the ground.Keeping snow cover will lessen the freezing.Dave

 

[Carl_NH]

Foam insulation under a deeper concrete 24" in the door area split inside and out - 4x8' along with rebar and stone for drainage ahould prevent the bad heaving. Should cut relief joints every 10' to prevent cracking of the slab.

 

[Egon]

I have found through trial and air that if you back fill holes with pea gravel and no dirt seems to work best.

This works because the pea gravel will not support capillary action which is essential to supply water to the frost lenses.

 

[SpringHollow]

My barns are built that way and we have heavy clay/shale so heaving is normally a problem. But i never have had problems with my man doors. (Pole barn - floating slab with gravel underneath.) Wish i could say the same with parts of the house.

Ken

 

[walleyed]

Building a pole barn. Poles set deep below frost line. Concrete floor/slab will be inside and "float" to allow for some movement if it needs to. Expansion material is attached around poles to keep floor from binding against poles along with natural shrinkage.

The 36" steel man door has a pole below frost line on either side to frame door. The question is what happens under the door where the slab is? Since the door will be attached to the poles it won't get heaved by frost. What about the part of the slab below the door? Could the concrete raise up and jam the door from opening?

JayCat

What I have done in the past is to frame the door opening extra wide(3") and taller then normal. Inside this opening i frame an actual opening for the door and attach it solid to the floor and only with lags into slots on the sides. This allows the door frame to slide up or down an inch or more with the floor. It takes an extra hour or so but the doors work.
Also you have to attach metal or what ever siding to the wall frame only and leave room for the door to move at the top. I hope that makes sense..