Weight Restrictions on Lap Joint Pergola

It depends on how long the lap joints are, what is holding them together and if the lap is vertical or horizontal.

It depends on how tightly the bolts are done up. Are there star washers in the lap joints? And nice big washers on the outside, to stop the nuts and bolt heads sinking into the timber.

Is there any diagonal bracing? If not, you might find it tends to go parallelogram shaped especially with adults swinging vigorously.

It also depends on how long the beams are, but I'm guessing it's a normal sort of size. Also, are the uprights set into concrete or metposts, or just standing on paving slabs?

Also, I am confused about what you mean about having two swings on two beams. Do you mean two parallel beams? Presumably this means the perpendicular beams are quite long, to prevent clashing? And if it is square, this means the cross beams must be quite long too.

The strength will also depend on the type and quality of the wood, but I have probably asked enough questions already. And I've probably missed a few.

Yes.

Yes its not the weight its the stresses if somebody actually swings. I guess you could just put a mattress underneath and wait for it to collapse! Brian

Post a photograph and folk can give you an informed guess, otherwise we're all just guessing.

Tim

No. He hasn't said how long the horizontal bars are and how well secured the verticals are, and as a pergola it will have no triangulation, which is even worse.