I plan to erect an aluminium pergola this weekend.
We have a slate patio (50mm thick). I have been advised that when fixing it down I should use a tile drill bit and drill slowly and then use Thunderbolts (self tapping concrete bolts) as the fixing instead of the shield bolts that it came with. Weights and straps etc will not work due to location.
The plate I need to fix to the ground for the legs has 7mm pre drilled holes in it. What I am wondering is do the holes for the thunderbolts need to be smaller than that so that they have something to bite into? I’ve not used them before. At the moment I can only find 7.5mm bolts so am wondering what to do. I am trying to work out what size drill bit and bolts I need to get. Don’t tell me drilling into slate is a bad idea. The pergola will have a cloth across the top so it needs fixing down. Appreciate the thoughts of the forum.
We have a slate patio (50mm thick). I have been advised that when fixing it down I should use a tile drill bit and drill slowly and then use Thunderbolts (self tapping concrete bolts) as the fixing instead of the shield bolts that it came with. Weights and straps etc will not work due to location.
The plate I need to fix to the ground for the legs has 7mm pre drilled holes in it. What I am wondering is do the holes for the thunderbolts need to be smaller than that so that they have something to bite into? I’ve not used them before. At the moment I can only find 7.5mm bolts so am wondering what to do. I am trying to work out what size drill bit and bolts I need to get. Don’t tell me drilling into slate is a bad idea. The pergola will have a cloth across the top so it needs fixing down. Appreciate the thoughts of the forum.
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