Enclosing Car Port

[Glenn42]

I inherited a garage with a 20x24 car port that is attached to the front with 4x6 post construction, There is 3" of blacktop under the car port, I have checked with my zoning board and they say it may be grandfathered in and not require footers which would be 48"x 48" by 16 inches wide for the posts, the current 4x6 posts are set in concrete but I do not no how deep, the structure is about 10 years old so it has stood that test of time, I want to build a 2x4 wall and want to know if I can build it with a plate resting on the blacktop, or does it have to rest on anything, I was going to have a builder do the job for me but the sale of my house does not allow the cost that it would require for him to do the job, he was drawing up plans and I offered to buy them, he was supposed to call me back but never did.
there is no blacktop between the posts so he had suggested putting the 2x4 walls inside the posts so that they could rest on the blacktop-----would this pose a heaving problem from freezing, is there something that could be put between the plate and blacktop (if it is necessary to rest it on something) that would mitigate any freezing and heaving problem.
Thanks, Glenn

 

[Shocker]

Hmmm, that is a tough call. Personally, I would not just set the walls on the asphalt.

I might look at digging down and putting in place some pre-cast pier blocks with the 4" mounting plate. Then secure them in the holes with cement. Run the wall down into those with a single pressure treated 2x4 on the mounting plates followed by the wall on top of that. It would assure a nice stable base for the wall.

Asphalt just wasn't designed to support a building.

That would

 

[Number21]

I have a "barn" attached to my shop that started as a carport years ago. Still has the gravel floor and the walls are simple 2x4 with thin chip board sheathing. The 2x4s rest on sort of a concrete "curb" that somebody hand poured, without a form, and, I think placed a 2x4 into the top of the wet concrete. My point is they didn't spend very much.

I have no idea if it's up to code, most likely not, but it's pretty old and still standing.

 

[autoist]

I'd use pressure treated for the bottom sill & go for it!

 

[Number21]

I'd use pressure treated for the bottom sill

Good point!

 

[Falcon67]

Depends on the lay of the land around the carport IMHO. Nothing less than a treated plate for sure. At a minimum to give the siding a chance, I would run a band made from 1x4 treated along the base of the wall, then start the siding on top of that. Screw the 1x4 banding to the studs and posts, then when it starts to **** out in years to come it can be easily replaced.

 

[Daniel Dudley]

It's basically a pole barn. Build it like a pole barn with a 2x8 PT laying horizontal on the ground and 2X stringers every two feet horizontally. Don't worry about the span between the posts, the 2X on the ground will prevent sagging.

Plenty of pictures of pole barns on this site that you can use as a model. If you have to put the stringers between the posts to make it slimmer for some reason, rip some 2X into vertical ledgers to apply to the sides of the posts as nailers.

Get a handy helper, and you will have the sheathing on in a day. You could use any type of sheathing you want, from metal roofing to OSB to T111. Keep it up on the PT, don't let it touch the ground

 

[Glenn42]

Thanks so much for the replys, I am going to attempt to get the permit by pouring 2 48" deep piers and bolting a treated 4x4 to those in between each post.
Thanks, Glenn