# Building a pergola, help me plan it!



## Double

Building a pergola with attached ground deck in a couple of weeks, just need to make some decisions on size, number of posts, materials, etc, so I can pick up all the supplies.

I've attached the basic layout below, I only have one workaround where there is a large tree that isn't going anywhere. I will post updated actuall measurement tonight after I can get out in the yard and lay it out in person.

This pergola is what I'm looking for, jsut a little different footprint:









The deck area will only be raised about 12 inches of the ground with one step, possibly even lower with no step below. 

So now the decisions to make:

1) I will be pouring footings, I assume in Sonotube, for the posts. How deep should they be (Dallas, TX), and should I set the posts into the cement or use anchors in the footings and then attach the posts.(The bottom of the posts will not be visible below the deck. If anchors, please recommend a style!

2) As you can see in the drawing, the outer posts will be on angled corners, do I need to set two posts at each corner so I can lag into the flat face of a post on each side, or can I attach the support beams on an angle with a beveled spacer of sorts?

3) I was thinking of a mixed material project to save on costs, with wood(PT Pine or Cedar) as the pergola/post frame material, and Trex or another composite/synthetic product for the decking.

4) I plan to have garden area at the corner where the fence comes together, and was thinking about using a clear corrugated plastic roofing, with rain chain and a french drain to help direct water there. Do you think this stuff will last/yellow over time? Is this jsut a terrible idea?

Like this:









Please respond with any and all assistance!

My budget is about $2500 for the yard this spring, and I was hoping to come in somewhere around $1000-$1500 for the pergola/deck. Is this realistic?

Hope to start digging post holes next week and build next weekend, or weekend after.


----------



## Daniel Holzman

You may want to check in first with the local building department. Typically decks/pergolas are built in accordance with some building code, in my town the code is the International Residential Code 2006 edition. When you pull a permit for a deck in my town, they give you the guidebook, which tells you pretty much everything you need to know about post sizes, spacing, connection details, joists, beams, decking, footings etc.

As for costs, I couldn't find the size you had planned, so I have no way to comment on whether your budget is reasonable. Also budget depends on materials used, different types of decking have very different costs. I built my deck using PT lumber for the framing, Ipe decking, cumaru for the rails, and aluminum balusters, total area was about 340 square feet, plus a staircase, material costs were somewhere around $8000 (this included a segmental concrete block wall entrance to my basement), so the overall material cost was about $25 per square foot. I imagine your cost will be significantly lower, since you do not have the staircase, you may not need railings, you are not planning to use ipe decking, and you don't have a retaining wall, but you do have a pergola which I don't have.


----------



## Double

> As for costs, I couldn't find the size you had planned, so I have no way to comment on whether your budget is reasonable.


I will post the size tonight when I get it measured out.



> You may want to check in first with the local building department. Typically decks/pergolas are built in accordance with some building code, in my town the code is the International Residential Code 2006 edition. When you pull a permit for a deck in my town, they give you the guidebook, which tells you pretty much everything you need to know about post sizes, spacing, connection details, joists, beams, decking, footings etc.


I'll look into the building department for permits/codebooks. Thanks!


----------



## Thurman

I've built a number of Pergola's in my area (S. Ga.) and there is a quirky little rule from the Code people: IF the Pergola will be attached to the dwelling in any way--permit needed. IF the Pergola is unattached--no permit needed. Just one nail driven through a board of the Pergola into the dwelling qualifies it as "attached". Quite frankly I've never understood why one would want a Pergola, except for aesthetic reasons. Here in S. Ga. they provide literally no shade.


----------



## joecaption

I have to agree with Thuman on this one. If it's shade you need, it's not the way to go.
I would never use that cheap plastic for a roof for all the reason you listed plus your trying to build this under a tree. Leaves, tannen stains, falling limbs are more reason to add to your list.
But ha it's your house.
A simple 12 X 12' deck with railings and composite decking cost me over $1970.00 for just materials and that's with no roof. 
I use a simple program to design decks call Big Hammer.
It will show the deck in 3D, show the post lay out, can adjust for differant loading, gives you a material list with upc codes directly from Home Depot, you can change decking direction, add stairs, walls or doors.
It has it's limits but it's worked for me.
I try to make all my single story decks free standing so I do not have to mess with the siding.
I also try to lay them out and over build them so if later someone wants to enclose it they can. Double rim joist, doubled 1/2 through bolted not nailed or lagged, 6 X 6's not 4 X 4's.


----------



## Double

Here's what I've found from the Dallas 3-1-1 site.
That is good info, I'll check into that program. I do plan on using 6x6 and through bolts with double rim joists and support beams.

This is not a shade stucture, mostly aesthetic, but also to create a separate area in the yard. If It turns out that shade becomes a priority, I have seen alot of people use solar screening like you woudl use on a sun facing windows.



> *NO PERMIT* is required for the following except in certain areas such as historic districts, conservation districts and planned development districts that have additional requirements.
> 
> *Erection of patio covers with an area less than 200 square feet on single-family or duplex premises (may not be within a front yard setback or side yard setback area)*
> 
> *Construction of decks, platforms, walks, or driveways not more than 30 inches above grade and not over any basement or story on single-family or duplex premises*


Also, I was able to locate the proper setback for the property:



> Zoning - R-7.5(A)​Single Family
> *Setbacks - Front- 25’ Side/Rear- 5’ *
> Denisty -1 Dwelling Unit/7,500 sq. ft.
> Height- 30’
> Lot Coverage- 45%
> Primary Use- Single family
> ​​


​


----------



## joecaption

By using 6 X 6's it also will allow you to cut into them so the rim joist are not just being attached to the sides of them.


----------



## Double

Good point...so on the double rim joist, I would have only the outer joist protruding from the post? And on the side joists, they would be fully "inlayed"? OR would you notch the post so the full double joist is inset?

I also have located some 5/4"x6"x16' Cedar 4 side smooth with roundover, boards for $10/board. They also have 14' for $9 and 10' for $6,* Is this a decent deal?*


----------



## joecaption

I cut the outside so the rim sits flush and use a forister bit the size of the 1/2 washers in the rim joist before drilling it so the bolt heads will sit flush, the inside one I just attach to the post. That way you have support for the decking when running it around the post.


----------



## Double

How about the height?

I would like to have enough room from decking to rafter so that I can hang baskets or a fan/light from the center. (This may end up as an unpowered structure, but I want the option.)

I know standard ceiling height is 8', so I was thinking somewhere between 8'-10' for deck to rafter, plus 1' for ground to deck height, and if I sink the post another 3', if I anchor it to footers, none added.

This would put 6"x6" posts max 16' length, min about 10'. Does that sound accurate. Trying to estimate project costs right now.


----------



## Double

Thinking:

Simpson PB66 for post anchors (http://www.strongtie.com/products/connectors/PB-PBS.asp#tables)
w/#10SD Screws(http://www.strongtie.com/products/connectors/PB-PBS.asp#tables)

Simpson LUS28 for joist hangers underneath decking (http://www.strongtie.com/products/connectors/LUS-HUS.asp)


----------



## joecaption

Now this is just my opinion but I would set my post below ground and set in concrete. Reason being is a Pergla has no walls so there going to be side sway, so unless you add a bunch of diagonial bracing it's going to sway if the post are just balanced on top of sonotubes.


----------



## Double

Ok, I will side with the experience here(3,500+ posts), so I assume since we have virtually no frost heave here, would 3' depth be plenty? 

Should I drive nails into the posts to help secure it in the concrete?
Should I pretreat the post or wrap it with anything?
Should I still use a Sonotube type product to shape the footer?


----------



## joecaption

Double said:


> Ok, I will side with the experience here(3,500+ posts), so I assume since we have virtually no frost heave here, would 3' depth be plenty?
> Yes
> 
> Should I drive nails into the posts to help secure it in the concrete?
> I never have before.
> Should I pretreat the post or wrap it with anything?
> Would not do any harm to use wood preserver or even foundation sealer. But I've never done it.
> Should I still use a Sonotube type product to shape the footer?


I just add some gravel in the bottom of the hole and add concrete around the post. I try to make my holes tapered so there wider at the top.


----------



## joecaption

Do not just judge by the number of post.
There's lots of members on here that know more then I do and as they get off work later in the day I'm sure there going to give you some differant ideas.
My way is not the only way.


----------



## Double

So the actual layout is somewhat revised based on the setback restrictions for Dallas.

Originally I was plannig for the width to go from 10' to 16' over the 10' depth of the pergola, but with the setback factored in the pergola will have to start much narrower and widen considerably more.

The only good news is that it completely takes the tree out of the picture, so I don't have to build around it.

The front span will be approximately 22' and the rear about 3'6". The right side 15' and the left side 15'6". The pergola depth will be 12'.


----------

