Pergola Help

[anojones]

We have a new concrete patio and hired a contractor to build a freestanding pergola on a portion of it- we've had other projects this spring and felt this was best left to a professional. The pergola is 4X4 redwood posts, with two 4X6 beams Simpson tied to the posts and 2X6 purlins (rafters?). The posts are attached with a Simpson post bracket that has been attached to the patio with tap-cons.
The problem is the pergola racks/wobbles a lot and is not stable enough at all. The contractors solution is to attach large T-straps from two or three of the 2X6 purlins over the gutter to the roof of the house bolted into the sub-fascia thru the roof shingles. I'm not thrilled with this plan, and my wife hates it. It was supposed to be freestanding and not tied to the house. Does anyone have advice on stabilizing this structure? We were thinking of adding a longer knee brace in addition to the one all ready there (so there would be two parallel knee braces). Perhaps hanging 4X4 beams in between and at 90 degrees to the current beams with knee braces. As you can see from the pictures, it has temporary bracing to keep the thing from coming down while we figure this out.

 

[flusher]

We have a new concrete patio and hired a contractor to build a freestanding pergola on a portion of it- we've had other projects this spring and felt this was best left to a professional. The pergola is 4X4 redwood posts, with two 4X6 beams Simpson tied to the posts and 2X6 purlins (rafters?). The posts are attached with a Simpson post bracket that has been attached to the patio with tap-cons.
The problem is the pergola racks/wobbles a lot and is not stable enough at all. The contractors solution is to attach large T-straps from two or three of the 2X6 purlins over the gutter to the roof of the house bolted into the sub-fascia thru the roof shingles. I'm not thrilled with this plan, and my wife hates it. It was supposed to be freestanding and not tied to the house. Does anyone have advice on stabilizing this structure? We were thinking of adding a longer knee brace in addition to the one all ready there (so there would be two parallel knee braces). Perhaps hanging 4X4 beams in between and at 90 degrees to the current beams with knee braces. As you can see from the pictures, it has temporary bracing to keep the thing from coming down while we figure this out.

Not surprising it wobbles--it's only braced sufficiently in one direction, namely in the direction of the knee braces.
I built this 20x20 ft pergola 4 years ago



Lotsa beams, cross beams and knee braces and very little wobble.

Looks to me like your contractor should have included two more beams perpendicular to the two already there and added four more knee braces to these extra beams. Then your pergola would be better stabilized.

 

[Mousefield]

Not surprising it wobbles--it's only braced sufficiently in one direction, namely in the direction of the knee braces.
I built this 20x20 ft pergola 4 years ago

View attachment 171276View attachment 171277View attachment 171278View attachment 171279

Lotsa beams, cross beams and knee braces and very little wobble.

Looks to me like your contractor should have included two more beams perpendicular to the two already there and added four more knee braces to these extra beams. Then your pergola would be better stabilized.

You are right; anojones needs to have more bracing in the other direction. Doesn't say much about the contractor :ashamed:, hope he doesn't build houses.

 

[rus_geek]

I agree with flusher. There is no bracing perpendicular to the house. I would add two more 4x6 beams with knee braces and it should lock together nicely.

-rus-

 

[beenthere]

I agree with rus geek, and his rendering of the added beams and braces.

I also don't like tieing in to the house through the roof shingles. Many things wrong with that.
Not the least, if around here that would add to the tax assessment of the house. :confused3:

The contractor or designer was not too experienced in structural work to have left out the bracing in one direction.

 

[anojones]

Thanks for the quick replies, the pictures are very helpful. Beautiful pergola flusher. Were now thinking of adding beams by bolting two 2x6s through the post just below the 4x6 beams (like a standard pergola) and adding 4x4 knee braces in between the 2x6s and to the posts. The 4x6 beams are expensive and hard to get and I'm not sure how to hang them at this point. It seems that the consensus is that tying the structure together will make a big difference.

 

[Danno1]

.

Also, those Simpson things at the top of the posts are just sheet metal. That's also part of your prob. Look at the way Flusher's beams are tied together.


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[Willl]

What the heck happened to that concrete finish ?

 

[anojones]

It's stamped and stained, actually looks nice in real life.

 

[ustmd]

I would not attach it to the house--that is a nightmare waiting to happen. If comes down in a storm, do you want it to bring part of the roof with it? Attaching it to the house is putting a band aid on bad design.

I have built four or five of these for myself, family members or friends.

I agree with Rus_geek on adding the 2x6s. The only addition I would make is that I would try to get the 2x6s to extend onto the 4 x 4s (1 on each side)and then bolt through (2 bolts) everything--which is what Flusher did on his.

Good luck and don't hire that contractor again or it was a kit, don't buy it again.