Timber Framed Pergola

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Project by Thepps posted 06-11-2013 01:17 PM 18131 views 37 times favorited 22 comments Add to Favorites Watch

This is an attached pergola built mostly out of western red cedar. The main front support 4×12 beam is Douglas Fir. I chose this for strength since it spans almost 18 feet. Everything else is cedar. No visible screws or nails. Lag screws were countersunk, then pegged. Rafters were toe-screwed from above. Shade planks were also screwed from above. Every board’s edges were rounded over with a router.

First off, this is not your usual looking pergola. I built it this way so it would fit our specific needs and to look unique. It is not a square design. The left post sits about 3 feet out of square. If I had built it square, the post would end up very close to the pool steps and would be quite obtrusive. 16’ overall length at the house, 21’6” overall length by the pool and extends 16’ from the house. About 10’6” tall.

There are exposed rafter tails on three sides and the rafters extend past the front support beam about 3’, which is longer than usual. We wanted to keep a comfortable distance from the pool to the posts, but also provide plenty of shade.

All of the 4×12 timber beams connect to the posts by a sliding tapered dovetail joint. A 10” powerlag screw went through each joint. The side 2×10 rafters also connect to the main rafters with this same joint.

All wood is rough
Posts – 8×8”
Support beams – 4×12”
Knee braces – 4×10”
Rafters – 2×10”
Shade planks – 2×6”

Now, to the timber framing:
I built jigs to enable me to cut these joints with a router. I bought the biggest dovetail bit I could find – Amana 45814 –
After some trial and error, I had a pretty accurate jig – similar to this : but with a much smaller price tag.

This is a sliding, tapered dovetail. It creates a very strong joint.

4×12 mortise jig

4×12 tenon

2×10 tenon jig

Built the entire pergola in shop. Stained in shop, also. Then moved it to the house and assembled permanently.

All of the beams are notched for the rafters.

After seeing the pergola installed, I did not like the short timber tails on the front. I made new, longer 4×12 timber tails to extend equally past the posts the same as the rafter tails. This also added some support to the some of the small rafters.

Attached to the bottom of the posts is a 1” polymer standoff, so the post does not sit in water when the concrete is wet. 1/2” rebar connects the post to the concrete

-- Thepps - Freeburg, IL

22 comments so far

View HorizontalMike's profile


7866 posts in 3646 days

#1 posted 06-11-2013 01:41 PM

WOW! Very nice! Not only is this a job well done, your presentation of the build is much appreciated here on LumberJocks. We all like to see the build portion of a project, and you provided much detail. Thanks! And Well Done!

-- HorizontalMike -- "Woodpeckers understand..."

View fernandoindia's profile


1081 posts in 3676 days

#2 posted 06-11-2013 01:58 PM

Thepps you made a great job there. Thank you for the construction process

-- Back home. Fernando

View vanessa22's profile


5 posts in 2543 days

#3 posted 06-11-2013 02:03 PM

Beautiful! great job

-- live life to the fullest!

View Sanding2day's profile


1015 posts in 2579 days

#4 posted 06-11-2013 04:20 PM

Very cool… Thanks for sharing all of the build info and pics! Nicely done!

-- Dan

View Mainiac Matt 's profile (online now)

Mainiac Matt

9517 posts in 3061 days

#5 posted 06-12-2013 12:57 AM

Looks great!

What kind of snow load do you get out in Illinois land.

-- Matt -- I yam what I yam and that's all what I yam

View Buckethead's profile


3196 posts in 2601 days

#6 posted 06-12-2013 02:11 AM

I’ve done a few dozen pergolas/arbors/trellises. None of them has utilized such joinery methods, or exacting techniques. I am truly impressed by your effort. I also like the way you adapted the shape to accommodate your needs. Very creative, and very beautiful.

-- Support woodworking hand models. Buy me a sawstop.

View JarodMorris's profile


167 posts in 3108 days

#7 posted 06-12-2013 03:03 AM

That is awesome. I’ve always wondered when you’re working on building one of these things and inevitably things go wrong, does it feel like you’re in pergolatory? ~Jarod

-- Dad: Someone was supposed to pick up his toys! Son: My name isn't "Someone".

View Hawaiilad's profile


3374 posts in 3753 days

#8 posted 06-12-2013 03:09 AM

What a great looking cover. I built one something like that years ago on a house we used to live on.

-- Larry in Hawaii,

View aussiedave's profile


3114 posts in 2556 days

#9 posted 06-12-2013 03:59 AM

Very nice pergola…great job….

-- Dave.......If at first you don’t succeed redefine success....

View JSB's profile


737 posts in 2810 days

#10 posted 06-12-2013 04:15 AM

Such a great project. Great documentation of it as well. You have a great place to enjoy the outdoors!

-- Jay -

View GRegghead's profile


5 posts in 2703 days

#11 posted 06-12-2013 05:43 AM

Beautiful work!
I’m about to start a pergola project, but it’s not going to have such fine joinery.

What stain did you use (brand and colour)? The dark colour looks great, but the grain still shows through nicely.


View JamieInIndy's profile


15 posts in 2634 days

#12 posted 06-12-2013 10:21 PM

I can’t say enough about your design. It’s just what I was looking for. Thanks for showing all the detail. I’ve been wanting to do something similar on our patio and this exceeds anything I’ve seen yet. Now I have my example to move forward. Just showed it to my wife and she’s liking it a lot! – got the green light ;). Thanks for showing!

-- Jamie - "Life's journey is not to arrive at the grave safely in a well-preserved body, but rather to skid in sideways, totally worn out and shouting, ".... holy crap....what a ride!"

View Thepps's profile


140 posts in 4486 days

#13 posted 06-13-2013 02:48 AM

Thanks everyone for all of the compliments.
Maniac Matt – Not much of a snow load for the St. Louis area, typically. I was walking on the top during installation and it feels very solid.
Buckethead – It was actually my wife’s idea to accommodate to the landscape. I would have made it square for ease of construction. But, it is better this way.
GRegghead – Cabot – Semi Transparent Burnt Hickory. Almost 5 gallons of it. Looked extremely dark when I stained it in the shop, but really turned out nice outside.

-- Thepps - Freeburg, IL

View arun's profile


4 posts in 2361 days

#14 posted 12-12-2013 11:02 AM

Really nice house building with woods. Here i suggest you to improve your outdoor living space with wooden decorations such as Pallets and frames.

View tincantimber's profile


2 posts in 1477 days

#15 posted 05-12-2016 05:38 PM

You did an awesome job replicating the Western Timber Frames ( product. How is it holding up 3 years later. I was toying with the idea of doing the same.

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