Top fitting roller blinds

[pmx_super]

I want to top-fit 3 x roller blinds in the recess of a 3-pane sliding door. Each blind will be 1.8m wide, 2.1m drop. Naturally we have a massive great steel spanning the gap above the doors with dot-and-dab plasterboard stuck to it. I've been put off drilling up into steel lintels by a semi-botched previous attempt in another room. It just didn't feel right and I have nowhere to practice.

I'm going to get motorised blinds, so my theory is that the downward force on the blinds will only ever be the weight of the blind itself (and not the tugging force of a human hand on the blind / pull-cord). On that basis I only need a fixing strong enough to hold the blind's weight, which would be about 5kg tops. Therefore I'm thinking 3 x GripIT fixings per blind (one in each of 3 x brackets) @12Kg each under tension force (https://www.gripitfixings.com.au/pages/gripit-table), gives me masses of headroom.

Can any of you bright folk see a flaw in my plan? E.g. would the dot-and-dab adhesive be strong enough? Are GripIT rubbish?

 

[Deleted member 174758]

I thought that GripIts were designed for hollowstud walls and ceilings,so the only problem I can see is that if you happen to drill the PB for the GripIt where there is a big dab you may find that you cannot extend the "ears" of the GripIt

 

[Alec_t]

Personally I wouldn't trust just fixing into plasterboard to take a vertical load. I'd pilot-drill into the steel and use slim self-tap screws into the steel.

 

[freddiemercurystwin]

Either use TEK screws (self tappers into the lintel) or this:

 

[pmx_super]

I thought that GripIts were designed for hollowstud walls and ceilings,so the only problem I can see is that if you happen to drill the PB for the GripIt where there is a big dab you may find that you cannot extend the "ears" of the GripIt

I figured I could mount brackets over the hollow sounding bits. Haven't actually tested that though, since I'll have to get lucky 9 times

 

[pmx_super]

This is the video I followed last time. It really didn't work. Maybe I should try Tek screws this time

 

[Deleted member 174758]

Self drilling screws are excellent for fixing stuff to structural metal. The only thing is, despite them being described as "self drilling", it's not unknown for them to require pilot holes first

 

[pmx_super]

Self drilling screws are excellent for fixing stuff to structural metal. The only thing is, despite them being described as "self drilling", it's not unknown for them to require pilot holes first

Just to provide closure, I used self drilling screws with pilot holes and it worked a treat. The key seemed to be using expensive and fresh drill bits, with diameter at the upper end of recommendation for screws. The self drilling screws would never self drill into my 20mm thick steel, but the drilly tip did seem effective at clearing the waste from the freshly drilled pilot holes.

 

[freddiemercurystwin]

20mm! You never mentioned that before! What the hell is above your window FFS?

 

[pmx_super]

20mm! You never mentioned that before! What the hell is above your window FFS?

I did describe it as a "massive great steel". 5.4m span. It's approx. 10mm I section with a 10mm plate welded on the bottom. Probably over specified tbh, like everything else the SE did. There's only about 3 courses of bricks above it, then a flat roof.