Anyone from NE climates, Carport input appreciated.

[Henry716]

I have researched and hoping for some up to date knowledge. I plan on building a lean to roof free standing carport to keep my travel trailer parked permanently on my land. Planning on building a 16ft wide by 40ft length. My travel trailer AC unit sits at 10ft 9in, so my height is going to be atleast that. I have 16ft 6x6 posts already. I've never been a fan of using concrete around posts and have been reading the treatment in PT lumber isnt what it use to be. People have recommended those wet set post brackets but I'm not sure I like that idea with post being atleast 11ft in the air (no experience using them.) My orginal plan was digging 48in down (frost line here is 42"), putting some gravel down and backfilling around the post with dirt. Am I over thinking this? Located in western NY. I'm not a contractor or soil analyst to determine what works for my needs. Carport will be sitting over a bank run pad. I appreciate all input.

Here's my building plans incase it helps makes a footer decision. 16ft 6x6 posts 10ft OC. 2x12 headers notched into the post with a 2x6 top plate. Then using rough cut 2x12x18 for roof trusses spaced 2ft OC burdsmouth cut sitting on each top plate. 2x4 purlins 2ft OC. Metal 18ft roofing. I havent figured my slope out yet for my roof.

Thanks in advance.
Side note* I BELIEVE I have the water drainage around where my carport will be all taken care of. Both sides will have about 1ft overhang. The low side of the roof will slope in the direction of the land away from the post. The high side of the roof ill make adjustments after a heavy rain if needed.

 

[Citydude]

Thanks for posting! I'm planning the same thing as you but on a smaller scale. I hope to learn from your project.

 

[Carl_NH]

Welcome to TBN!

The roof pitch is probably your biggest challenge - as a 4/12 pitch would mean the high side needs to be about 13.5' out of the ground and the low side would be 10'. The mid point height assuming the AC unit is centered on the trailer needs to be about 11' (13.5'-32" =10.8')

IMO you would be better suited to a traditional roof design with a 6/12 or 8/12 pitch and then your posts could be 4' in the ground all around. As far as concrete vs your tamped/stone if you have good drainage and 4'+ in the ground you should be OK - I would put a concrete base in the hole to prevent sinking or movement.

 

[BoylermanCT]

You are basically building an open air pole barn. I framed and roofed my 30x40 pole barn last fall. The plans for my barn called for 48” holes for the triple lam 2x6 posts with 18” 2x6’s attached horizontally near the bottom of the post for uplift prevention. If you are using rafters and not trusses, make sure you brace them well so they don’t push the walls out and allow the roof peak to sag. My old barn did that which is one (of many) reasons I replaced it.

 

[Henry716]

Welcome to TBN!

The roof pitch is probably your biggest challenge - as a 4/12 pitch would mean the high side needs to be about 13.5' out of the ground and the low side would be 10'. The mid point height assuming the AC unit is centered on the trailer needs to be about 11' (13.5'-32" =10.8')

IMO you would be better suited to a traditional roof design with a 6/12 or 8/12 pitch and then your posts could be 4' in the ground all around. As far as concrete vs your tamped/stone if you have good drainage and 4'+ in the ground you should be OK - I would put a concrete base in the hole to prevent sinking or movement.

Thanks for your response and the math is appreciated haha. I was figuring the snow load contributed to the slope issue..if I did 16 centers do you think I can keep my design and have a 2.5 foot slope? 12.5 high side 10ft low. Not sure the requirements for weight load vs water runoff... also can I do like a double top plate to increase my height on the high side? Only asking because I had the 18ft tin laying around I was hoping to use

 

[Henry716]

You are basically building an open air pole barn. I framed and roofed my 30x40 pole barn last fall. The plans for my barn called for 48” holes for the triple lam 2x6 posts with 18” 2x6’s attached horizontally near the bottom of the post for uplift prevention. If you are using rafters and not trusses, make sure you brace them well so they don’t push the walls out and allow the roof peak to sag. My old barn did that which is one (of many) reasons I replaced it.

Good insight! Thank you

 

[jthibodeau89]

With the current $$$ of dimensional lumber, may want to consider steel bar joists at each post and just 2x8 purlins 24"OC. If you have a sawmill nearby, thay may help, since appears the folks making the $$$$ are the 6 main corporate lumber mills (based on their stock reports).

 

[Henry716]

With the current $$$ of dimensional lumber, may want to consider steel bar joists at each post and just 2x8 purlins 24"OC. If you have a sawmill nearby, thay may help, since appears the folks making the $$$$ are the 6 main corporate lumber mills (based on their stock reports).

I have many amish mills near by..they're still backed up, but more logs are coming in every day. I'm in the early stages of planning due to the high prices..im fortunate enough to had the 6x6 post and metal already..just hoping I can make them work. I never thought about steel before..thanks for the idea. I'll look into it!

 

[jthibodeau89]

Here' a pic of our 48x108 horse barn. Center aisle is 24' wide. 16' wide will likely not have the full width tension member. Truss design has evolved. Latest designs have a 2x depth drop at center and just bolt together. This barn is 22 yrs old.

 

[fruitcakesa]

My shop is essentially a pole building just heavier built.
Since the drainage around it is poor I went the following route:
We dug 4 to 5 foot deep trenches around the perimeter and center and placed 16" inch plastic culverts vertically wherever a post was to be.
The bottom 6" of the culverts were slotted to allow water to drain out.
Large flat stones were put in the bottom of the holes and 8x8 PT posts were dropped down onto the stone.
The culverts were then filled with crushed stone.
We put french drains in the trenches run out to clear air and then backfilled them.
The posts were about 14 feet total length to give around 9 foot ceiling height.
Roof is a full gable style with a 12/12 pitch and metal roof.
After 20 plus years it is as solid as the day it was built.