free standing patio cover still has some sway

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Old 09-23-13, 06:50 AM
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free standing patio cover still has some sway

New here. I built a free standing 12'x16x patio cover all wood construction. 6 4x6 posts, dbl 2x10 beams, 2x8 on 16" rafters, osb sheathing, asphalt shingles, 4x4x27" knee braces on every post to beam joint. I also have 3 4x4's that span between the posts from the house side to the end with knee braces there. I can not attach to house due to brick veneer. I used Simpson post supports wedge anchored into existing slab. (I know not ideal) I still have some movement even after all of the knee braces. Very little maybe an inch at the roof line with me pushing quite hard on the posts. Is this normal/OK or is there something else I should do. House side roof line is 9' end side is 8'.
 

Last edited by dsternke; 09-23-13 at 06:58 AM. Reason: additional info
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Old 09-23-13, 07:21 AM
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Post a picture.
If this is a single story house the patio roof should have been run up onto the house roof, not attached with a ledger.
 
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Old 09-23-13, 08:11 AM
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I do not have a ledger. It is free standing, sloping away from a 2 story brick house.
 
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Old 09-23-13, 08:35 AM
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Old 09-23-13, 10:04 AM
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There are a few areas that could be causing your sway problem.

1. Inadequate fasteners at the ends of the diagonals, allowing some movement to take place (that tight through-bolts, instead of your wood screws, would prevent).
2. Possible weak anchor bracket connections at the column bases, allowing the columns to rotate slightly when loaded from the sides.
3. Columns having a weak axis, which is less able to resist side loads than the strong axis direction. Using 6 x 6 columns would have been a better option.
 
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Old 09-23-13, 10:29 AM
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Thank you Bridgeman and Joecaption for your replies. Bridgeman, in hind sight the 6x6's should have been used. I used 6" lag screws in the diagonals and they seem really tight. I could go back and use through bolts on all of the joints except for those against the house if it would really add that much strength. I would welcome any ideas to strengthen my post support to the concrete. Again the movement is not that much but did not know if it is a major concern.

Thank you for your advice.
 
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Old 09-23-13, 05:28 PM
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I feel better after seeing your pictures. I had nightmare scenarios running through my head until I saw you were not doing it on the cheap. I am going to pick holes at it but I'm not trying to be an Ahole. It's obvious you put a lot of work into the structure.

If you have a helper available put your finger against the joints of your diagonal braces and have the helper give the roof a shove to make it move. If there is movement in your joints it should be easy to feel. If you feel movement at the joints you know where you need to do more work. If you don't feel movement in the joints then the vertical posts bending is more a possibility.

I think one issue is the length/location of the corner braces. They may be securely attached but they are leaving 3/4 of the column unbraced. You may have the top 2' of your posts securely braced but the rest of it is free to bend. Worst is shown in the photo "bracing3". The diagonal brace on the gable end just goes to some spot along a long horizontal. If you push sideways on that column the diagonal is pushing/pulling on the horizontal beam, which being long and straight with no bracing is quite flexible so the diagonal going to it does very little. In the other direction your 2x10 beam is very strong to resist bending in that direction so the bracing is much more affective.

You're well inland and it looks like you've got protection from the surrounding trees/forest but if I'm nit picking... You've used "hurricane straps" to attach the rafters to the beam but I don't see any other brackets to transfer the load down to the ground. Strapping the rafters doesn't do much good if the beam is not secured.
 
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Old 09-23-13, 06:40 PM
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Thank you for your input Pilot Dane. The movement appears to be in the posts flexing. With that being said is it possible for me to bolt an additional 4x6 to each post and attach to the 2x10s? I am over 200 miles from the coast and little to no snow load and very little in the form of strong winds. As a footnote I did lag the beams to to the posts and also used a Simpson flat bracket on each of the post to beam joints. Is there something more I should have done. Currently do I have a concern that the 4x6s could fail? Once again thanks for every ones input.
 
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Old 09-24-13, 02:21 PM
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Today my son and I added an additional 4x6 to each post on the tall end of the patio cover. We also double the length of the diagonals. The roof is now stable to the point where I am comfortable that when I flash the roof to the house it will not move. We through bolted the additional posts to the existing ones and added a Simpson post to beam bracket. Diagonals are now 4' rather than 27". I want to thank everyone who had input in this issue and look forward to the next project where I can get input BEFORE I encounter a problem.
 
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