Diy free standing pergola - advice needed

[raeoflyte]

I have 1 section of patio that isn't covered, on the east side which means the sun heats up practically the entire patio until 1 or 2pm in the afternoon. I've tried a store bought gazebo, and a shade, but neither worked well.

My latest idea is a free standing pergola, but I need help figuring out what size boards I need to make sure its solid.

The area is 11ft by 13ft. The 4 corner posts are/will be 4x4's in half whiskey barrels filled with 150 pounds of concrete each. Posts are 86 inches tall. I'd like to run 2x4's from each post to make the perimter and then run 8 rafters length wise across the top. I was thinking to have the rafters extend past the posts on 1 side so 14 ft rafters across the top. We'd put a sun shade on the top when using, but would be open in the winter so it wouldn't hold much extra weight from snow.

If any of this makes sense, would 2x4's be strong enough? If not, what size/material should I get? And what size boards should I use for the rafters?

[Happy prose]

Sorry, I have no idea, but I admire your ambition! Post a pic when done.

[mroped]

Ok! Here we go:
- you can do what you described above if you plan on replacing it/ fixing it every couple years or...
- dig holes for the corner posts- I’d go about 36” deep and at least 12” diameter on each hole. The bottom needs to be solid, undisturbed soil or thoroughly tamped. Fill the holes with concrete to the top. Insert at least 2 pieces of steel in each for the whole dept.
- get a shoe/ boot made or bought for each of the hole. They are a “U” shape and get affixed to the concrete with anchor bolts when the concrete is fresh or with thunder bolts/tap cons if the concrete is cured.
- for posts I’d recommend 6”x6” treated lumber of at least 98”(8’) long. Insert them in the shoe/ boot and fasten it 
- along the 13’ side I’d run double plates 2x6 treated( one on each side of the post). 14 or 16’ long and leave overhangs on ends.
- at this point you can run 2x6s treated spaced at 2’ along the 11’ side resting on the plates running the other direction.
- only then you can run 2x4s( but not necessary- you can get away with 1x4s) on the grid to support whatever plants you might have in the future.

You will end up having about 450# of concrete on each post.
I would not insert the posts into concrete. The lime and all other chemicals in the mixture will decay the wood at a rapid rate and snap the posts. That’s why the shoe/boot to separate wood from concrete.

[tskeeter]

While I agree with mroped, there are some considerations you should keep in mind.  

In our area, structures such as pergolas are subject to local building codes. They must be built to accommodate specific snow and wind loads and have limitations on how long the span between support posts can be, depending on what materials you use.  The code also specifies the size of the footings that are required.  (Our free standing pergola required a 3X3X3 foot concrete footing, about 4,000 pounds, for every 100 square feet of pergola.). Remember, building codes are about safety.  You don’t want your neighbors to be injured by airborne debris that used to be your pergola.  Or have your family injured in a pergola collapse.  I think a chat about your plans with your local building department is in order.

[mroped]

Yes, then is that:codes!
What I said above is passing codes for Central Pa: 32” frost, 40#/sf snow load, 60MPH winds.
you can also go with standard timbers for the frame but they need to be bigger.

[Lizard Queen]

How about a metal, pre,built one? No worries about building codes, and easier to put up.

[hoops902]

So at 86" high, I'd use 6x6 posts.  The perimeter sizing I would suggest is 2x6.  I don't like 2x4s for anything spanning that much.  Use whatever you want for the rafter piece, 2x6 is probably fine and the real issue will just be figuring out how much you want to space them out for blocking the sun.  Everything should be treated/suitable for weather exposure.  Obviously I have no idea what your building codes are, nor the building codes in general for a pergola. Anything greater than a 2x4 though I tend to not worry much about the span given it's going to have no load on it.

[raeoflyte]

Jun 23, 2019 18:50:32 GMT -5 mroped said:

Ok! Here we go:
- you can do what you described above if you plan on replacing it/ fixing it every couple years or...
- dig holes for the corner posts- I’d go about 36” deep and at least 12” diameter on each hole. The bottom needs to be solid, undisturbed soil or thoroughly tamped. Fill the holes with concrete to the top. Insert at least 2 pieces of steel in each for the whole dept.
- get a shoe/ boot made or bought for each of the hole. They are a “U” shape and get affixed to the concrete with anchor bolts when the concrete is fresh or with thunder bolts/tap cons if the concrete is cured.
- for posts I’d recommend 6”x6” treated lumber of at least 98”(8’) long. Insert them in the shoe/ boot and fasten it 
- along the 13’ side I’d run double plates 2x6 treated( one on each side of the post). 14 or 16’ long and leave overhangs on ends.
- at this point you can run 2x6s treated spaced at 2’ along the 11’ side resting on the plates running the other direction.
- only then you can run 2x4s( but not necessary- you can get away with 1x4s) on the grid to support whatever plants you might have in the future.

You will end up having about 450# of concrete on each post.
I would not insert the posts into concrete. The lime and all other chemicals in the mixture will decay the wood at a rapid rate and snap the posts. That’s why the shoe/boot to separate wood from concrete.

A permanent structure turns this from DIY, to hiring out and likely waiting until fall for it to be done. I can dig post holes, but not when I have to jackhammer up parts of the existing patio to do so.   If we like this layout though, we may go permanent down the line.  

I'm not planning on a grid for the top, just 1 direction rafters so a little lighter, and I can get at least 250 pounds of concrete in each planter.  Probably 300, just couldn't re-use them then for planters really.  We won't do any vining plants that would add weight to it, just the sun shade in summer.  So  6x6's for posts, and then double 2x6's for the perimeter, and 1x4's for the rafters -- does that sound like it would work?  

[raeoflyte]

Jun 23, 2019 20:03:57 GMT -5 tskeeter said:

While I agree with mroped, there are some considerations you should keep in mind.  

In our area, structures such as pergolas are subject to local building codes. They must be built to accommodate specific snow and wind loads and have limitations on how long the span between support posts can be, depending on what materials you use.  The code also specifies the size of the footings that are required.  (Our free standing pergola required a 3X3X3 foot concrete footing, about 4,000 pounds, for every 100 square feet of pergola.). Remember, building codes are about safety.  You don’t want your neighbors to be injured by airborne debris that used to be your pergola.  Or have your family injured in a pergola collapse.  I think a chat about your plans with your local building department is in order.

I will see what I can find online or give them a call if needed.  Good advice!

[raeoflyte]

Jun 24, 2019 5:54:57 GMT -5 Lizard Queen said:

How about a metal, pre,built one? No worries about building codes, and easier to put up.

They fall apart so quickly for how much they cost, and they all seem to be pretty small for the pergolas.  We used one of the pre-built gazebos when we first moved in, but it didn't last at all.  

[hoops902]

Jun 24, 2019 9:34:15 GMT -5 raeoflyte said:

Jun 23, 2019 18:50:32 GMT -5 mroped said:

Ok! Here we go:
- you can do what you described above if you plan on replacing it/ fixing it every couple years or...
- dig holes for the corner posts- I’d go about 36” deep and at least 12” diameter on each hole. The bottom needs to be solid, undisturbed soil or thoroughly tamped. Fill the holes with concrete to the top. Insert at least 2 pieces of steel in each for the whole dept.
- get a shoe/ boot made or bought for each of the hole. They are a “U” shape and get affixed to the concrete with anchor bolts when the concrete is fresh or with thunder bolts/tap cons if the concrete is cured.
- for posts I’d recommend 6”x6” treated lumber of at least 98”(8’) long. Insert them in the shoe/ boot and fasten it 
- along the 13’ side I’d run double plates 2x6 treated( one on each side of the post). 14 or 16’ long and leave overhangs on ends.
- at this point you can run 2x6s treated spaced at 2’ along the 11’ side resting on the plates running the other direction.
- only then you can run 2x4s( but not necessary- you can get away with 1x4s) on the grid to support whatever plants you might have in the future.

You will end up having about 450# of concrete on each post.
I would not insert the posts into concrete. The lime and all other chemicals in the mixture will decay the wood at a rapid rate and snap the posts. That’s why the shoe/boot to separate wood from concrete.

A permanent structure turns this from DIY, to hiring out and likely waiting until fall for it to be done. I can dig post holes, but not when I have to jackhammer up parts of the existing patio to do so.   If we like this layout though, we may go permanent down the line.  

I'm not planning on a grid for the top, just 1 direction rafters so a little lighter, and I can get at least 250 pounds of concrete in each planter.  Probably 300, just couldn't re-use them then for planters really.  We won't do any vining plants that would add weight to it, just the sun shade in summer.  So  6x6's for posts, and then double 2x6's for the perimeter, and 1x4's for the rafters -- does that sound like it would work?  

Make sure you do something to keep water out of the concrete-filled planters then.  You want to keep the moisture away from pooling against the wood.  And you only need double 2x6s on the 2 sides that will support the rafters, not around the entire perimeter (the 2 ends that don't carry the weight of the rafters aren't doing anything, you don't even need 2x6s on the perimeter there, the rafters will produce the same effect having perimeter boards there would.  

[raeoflyte]

Jun 24, 2019 9:54:23 GMT -5 hoops902 said:

Jun 24, 2019 9:34:15 GMT -5 raeoflyte said:

A permanent structure turns this from DIY, to hiring out and likely waiting until fall for it to be done. I can dig post holes, but not when I have to jackhammer up parts of the existing patio to do so.   If we like this layout though, we may go permanent down the line.  

I'm not planning on a grid for the top, just 1 direction rafters so a little lighter, and I can get at least 250 pounds of concrete in each planter.  Probably 300, just couldn't re-use them then for planters really.  We won't do any vining plants that would add weight to it, just the sun shade in summer.  So  6x6's for posts, and then double 2x6's for the perimeter, and 1x4's for the rafters -- does that sound like it would work?  

Make sure you do something to keep water out of the concrete-filled planters then.  You want to keep the moisture away from pooling against the wood.  And you only need double 2x6s on the 2 sides that will support the rafters, not around the entire perimeter (the 2 ends that don't carry the weight of the rafters aren't doing anything, you don't even need 2x6s on the perimeter there, the rafters will produce the same effect having perimeter boards there would.  

Good points -- thank you!  

[bobosensei]

Have you thought about those adjustable awnings?  My sister's neighbor got some like you see advertised on tv infomercials.  They only roll it out when they want to use it, and otherwise it isn't out in wind or rain storms.  Seems to work well for them.

[thyme4change]

Costco and Sam's Club has kits.

Have you considered sails? Cheap, fast, easy.

[raeoflyte]

Jun 25, 2019 10:47:11 GMT -5 thyme4change said:

Costco and Sam's Club has kits.

Have you considered sails? Cheap, fast, easy.

I hadn't...but I am now.  Thank you!!