Pergola construction advice

[DomLeps]

Hi,

I'm planning to put together a DIY wooden pergola this weekend. I've got a patio that's 5500mm x 3000mm and has been laid with 22mm Kandla sandstone slabs on a bed of wet mortar.

I'd like my pergola to cover the whole patio, so be at least 3000mm x 5500mm.



I have access to the soil on either side of the 3000mm lengths of the patio where I can dig footings for the pergola posts and concrete them in. However, I don't have access on the 5500mm sides as this contains slabs.



Originally I was planning to have 6 posts - but this would involve having two posts landing directly in the middle of the patio - and i'm not sure how im going to lift slabs in the middle of the patio easily



I was wondering if I can get away with just having 4 posts for a pergola of this size? That's my ideal configuration.



If not could i just use post bases for the two posts that will land on the patio such as these? (https://www.indooroutdoors.co.uk/pr...MIhtbOhPmihQMVMJFQBh3J9gZjEAQYASABEgLG-fD_BwE)

or would that not be structurally sound



Thanks for any advice you can give



Dom

 

[Notch7]

I suppose you could sit the middle ones on the patio slabs with those post bases.

The middle ones would take the downward load but wouldn’t contribute to lateral stability.

Can you have 3 posts concreted in on the 3 metre sides to make the pergola stiff.

I’d use flashband on the ends being concreted to prevent rot - use a heat lamp and seam roller to stick them on nice n tight - or buy post savers