Attach pergola to external wall (side on)

[RazzyRascal]

Hi All,

Thanks for stopping by.

I'm soon to be building a 4m x 3m lean-to pergola in my garden which I will affix to a masonry wall. This wall is the end of my detached garage which i have converted into garden room with patio doors opening onto a deck and is approached side-on.

The idea is to build a pergola with the cross-members running parralel to the garage wall; for aesthetic reasons this is the angle of approach, and the deck is at a slight angle so i can cut these neatly to line up with the decking layout below.

Most imagery of lean-to pergolas show the crossmembers perpendicular to the walls, mounting onto a wall fixed ledger board at pre-determined intervals. Now, because i am running my cross members parralel i have no need to mount these to a ledger as they will be supported by the pergola frame, which will be a cube arrangement of 150mm posts (2nr uprights and 3nr rafters).

As a consequence i will only need to fix 2 of the 150mm posts to the wall at approx. 3000mm centres. I'm thinking something like this - https://www.indooroutdoors.co.uk/pr...table-for-6-x-6-timber?variant=43780736057565

The garage was built mid-90s and is solid Ashdown brick so baked solid like ceramic.

The question is, how would an experienced chippy / builder fix to the masonry in this instance?

(Rough image of structure attached)

Thanks! Razz.

 

[simplesteve]

Personally, I’d still run a full length along the garage wall, and ‘rest’ your 2 frame lengths on top of it, just to spread the load evenly.

 

[RazzyRascal]

Personally, I’d still run a full length along the garage wall, and ‘rest’ your 2 frame lengths on top of it, just to spread the load evenly.

Thanks for the response Steve

 

[johnny2007]

Personally, I’d still run a full length along the garage wall, and ‘rest’ your 2 frame lengths on top of it, just to spread the load evenly.

Yes, do this

 

[Tigercubrider]

Mine is about 3x3m and fixed to the rear of a single storey 1980’s extension to the house, brick construction so pretty much what you have. Mine slopes away from the extension, so 90° to your plan but I think the same idea.

As above, I would fix a batten to the side of the garage, along the face, angled to suit your pitch.
You have the option of Rawl bolts, Frame Fixers, Resin Anchors.
The actual load of a pergola is minimal if it doesn’t have a roof.

Mine is covered in a grape vine (6 plants) so when it’s more likely to have high winds or heavy rain, the foliage is gone and the load is minimal. There is no snow load.

Don’t bother with posts on the garage unless it’s an aesthetic choice.
If aesthetic, you could use half posts as on a newel post but I would do neither.

 

[RazzyRascal]

Mine is about 3x3m and fixed to the rear of a single storey 1980’s extension to the house, brick construction so pretty much what you have. Mine slopes away from the extension, so 90° to your plan but I think the same idea.

As above, I would fix a batten to the side of the garage, along the face, angled to suit your pitch.
You have the option of Rawl bolts, Frame Fixers, Resin Anchors.
The actual load of a pergola is minimal if it doesn’t have a roof.

Mine is covered in a grape vine (6 plants) so when it’s more likely to have high winds or heavy rain, the foliage is gone and the load is minimal. There is no snow load.

Don’t bother with posts on the garage unless it’s an aesthetic choice.
If aesthetic, you could use half posts as on a newel post but I would do neither.

Thanks Tiger.

Yes, no posts on garage only the two main support joists.

There won't be a pitch to this, unless its an ergonomic requirement? I know that its popular to pitch the cross members downward away from buildings for aesthetics (and runoff?!) but mine will be parallel so its not been a consideration. To clarify, like yours mine will be for supporting plants, so no roof.

 

[Tigercubrider]

Mine slopes just to aid shedding rain.
However when the leaves are out, I doubt that there is no benefit.
I’m not even sure that, if in mid winter when there are bare twiggy stems all over it, much if any moisture falls off.

 

[RazzyRascal]

Mine slopes just to aid shedding rain.
However when the leaves are out, I doubt that there is no benefit.
I’m not even sure that, if in mid winter when there are bare twiggy stems all over it, much if any moisture falls off.

Makes sense. I've plumbed for C24 timber anyway - i'm not overly concerned about moisture shedding for the structure above ground and instead will concentrate my efforts on the decking sub frame and pergola footings.

Thanks for everyones input, following feedback from a structural engineer i've opted for 2nr joist hangers anchored into the masonry.