Fixing Gazebo to raised patio

the_lunatic_is_in_my_head

Don’t know if you have your gazebo yet OP?

If not we have this kind of thing:

https://www.whitestores.co.uk/shadow-metal-pergola-in-graphite-grey-2-4m-x-3-0m-free-standing?gad_source=1&gad_campaignid=17347810025&gbraid=0AAAAAD-8ZLRa3PGfjtkUVP3Opm9ep9-qE&gclid=EAIaIQobChMIlKL35dWEjwMVG6BQBh2LrzJWEAQYASABEgIxEfD_BwE

It comes with bolts and you can open the roof to reduce the risk of the wind lifting it up on windy days. 

They are a bit pricy but easy to put together and decent quality.

As above I’d lift the slabs where the posts are going, dig down, fill with concrete, relay slabs and then drill down for the blot.

Ideally you want the post centre of the slabs, drilling to close to the edges could result in the slabs cracking. 

FreeBear

bjorn_toby_wilde said:

You could bolt it down with rawlbolts if there are holes in the feet of the gazebo.

Sandstone is pretty soft and easy to drill with a masonry bit.

Use longer ground screw - Numerous lengths, styles, and types available. I'm sure an "off the shelf" product could be found. Would look better than lifting a slab and replacing it with concrete.

Lummoxley

Thanks all, @FreeBear, I was going to use long ground screws but I didn't think the ground conditions under the slabs were suitable.

Eldi_Dos

@Lummoxley
If you are wanting to improve the stability of the material under your slabs without lifting them you could inject a grouting mix in below the area where your fixings are going to be.

A cheap and cheerful method:
Buy a Halfords 20 Litre Water Carrier. (part no 355462)
2 Schrader Valves + Suitable size of plastic tube to fit over schrader valve stem + Various Rubber washers + Hose Clip.

Fit one complete valve to the screw on lid of water container
Fit the other valve stem (minus the valve parts, which are easily removed) to container  NB:

To make it easier to get valve in place drop a length of string down into container and hook out with a bit of wire or long nosed pliers, at other end pass string through washers and valve stem then tie suitably large knot on string, leaving enough string so you can recover it once valve fitted.Then use to position and pull through hole and fit washer and tightening nut, and recover string.

Fit plastic tubing to valve stem with hose clip.

When you know the fittings you are going to use to hold wooden posts in place, drill holes through paving to suit, then use a probe to make hole through material under paving.

You can then mix up a grouting mix into the water carrier,put on lid and using a bike or footpump add a bit of pressure to container and inject grouting mix down the drill/ probe holes.I would caution not to be tempted and add too much pressure.

I realise its a bit Heath Robinson and inexact but would save digging up the paving and give a better grip for whatever fixings you use.