Need help with pole barn overhead detail - Concrete next week!

[DrewStyduhar]

We are going to pour concrete late next week and a thought just occurred to me about the overhead door openings. As things sit, the plan is to put a form board on the outside of the door jamb trim and pour the concrete right up to the tin in the door openings. I didnt think/realize that concrete against tin is not cool so I need to figure out what to do asap.

I have attached a pic showing one side of the opening. Note the non PT 2x4 attached to inside of post and left long so the door wont fall out of the track before concrete is poured. This will get cut off flush before pour but thats what is behind the tin if its cut away. Sort of tough to tell but the building has two rows of skirting so there is a row of tin below the rat guard that turns into the door openings. If you cut the door jam trim, this second tin layer is underneath. Cut that away and its the non PT 2x4. Remove the 2x4 and you are looking at the post.


Orange line is grade of concrete inside building
Red line shows 1/2" drop from door track to outside to help shed water.
Blue line is just a rough guess of where I would cut the trim to keep it above the concrete.

Here are some ideas

1. Leave as is but put tarpaper or foam on the tin so it doesnt rust
2. Snip the jamb trim 3/8" above the red line and cover the remaining exposed tin/wood with tarpaper

thank for any ideas or advice.

PS - dont mind the foam in the pic, its used to keep critters out of the barn.

thanks,

Drew

 

[dlctcg]

You could just wrap the section with Grace Ice and Water Shield (or equivalent)... Leave it a little high but only cut away the adhesive side to cover the concrete pour line, then after the pour cut off the excess. It will be nice & clean, adhere to the structure where needed, watertight & unnoticeable after being trimmed. (Also leave so fudge factor for the pour)

 

[Hay Dude]

Snip the tin, but bend it like flashing at an angle to kick water away. Put typical rigid foam under your new flashing against treated board, then concrete.

 

[LD1]

Is it treated wood behind the tin? OR is the tin there to protect untreated lumber?

IF its treated behind the tin I'd snip and remove.

Personally I dont like the gradual slope away from the door. I like a lip/step cut in that the door closes against. IE: The inside floor is 1" higher. The door closes 1" BELOW the floor level. So everything outside the door is lower.

Any wind blown rain wont jump up the 1" lip and be inside the barn. But as you have it now....a windblown rain blowing toward the door is gonna run across the floor to wherever your drain is.

This is a pic of a buddies barn we just poured back in the early spring. This is the IDEAL garage door transition. IF you have a GOOD concrete contractor they will know exactly how to do this.

 

[DrewStyduhar]

You could just wrap the section with Grace Ice and Water Shield (or equivalent)... Leave it a little high but only cut away the adhesive side to cover the concrete pour line, then after the pour cut off the excess. It will be nice & clean, adhere to the structure where needed, watertight & unnoticeable after being trimmed. (Also leave so fudge factor for the pour)

Thanks for the advice.

 

[DrewStyduhar]

Snip the tin, but bend it like flashing at an angle to kick water away. Put typical rigid foam under your new flashing against treated board, then concrete.

Thanks for the advice. How would you cut the tin without making it look wavy and rough? I would be worried about foam collecting water.

 

[DrewStyduhar]

Is it treated wood behind the tin? OR is the tin there to protect untreated lumber?

IF its treated behind the tin I'd snip and remove.

Personally I dont like the gradual slope away from the door. I like a lip/step cut in that the door closes against. IE: The inside floor is 1" higher. The door closes 1" BELOW the floor level. So everything outside the door is lower.

Any wind blown rain wont jump up the 1" lip and be inside the barn. But as you have it now....a windblown rain blowing toward the door is gonna run across the floor to wherever your drain is.

This is a pic of a buddies barn we just poured back in the early spring. This is the IDEAL garage door transition. IF you have a GOOD concrete contractor they will know exactly how to do this.
View attachment 764730

Hello. The 2x4 is untreated. The barn was raised up and a second PT skirt added and turned into the door opening. I guess I could replace the 2x4 with a PT piece but I really dont have the time to tear into things that much.

I like that lip detail. Would be concerned about rolling things in and out of the shop. I understand what you are saying about the slope. My plan was to have the slope start behind the door seal so even if water gets behind the door it will still be fighting uphill battle. Maybe Ill move the beginning of the slope to the rear track

 

[ROUSTABOUT]

Thanks for the advice. How would you cut the tin without making it look wavy and rough? I would be worried about foam collecting water.

Cut tin straight so it won't be wavy. Foam is expanded or extruded. So get foam that doesn't absorb water.

 

[DrewStyduhar]

Cut tin straight so it won't be wavy. Foam is expanded or extruded. So get foam that doesn't absorb water.

Would I cut both layers or just the door jamb outer layer? If I cut both then that non PT 2x4 is there exposed between bottom of the tin and top of concrete.

 

[DrewStyduhar]

Cut tin straight so it won't be wavy. Foam is expanded or extruded. So get foam that doesn't absorb water.

I'm not talking about not being able to cut on a line, I'm talking about the waviness that happens when cutting with shears.