Preparing stud wall holes for redrilling

[Widgets]

First post; Building or General forum? I've decided the former, but please be gentle if wrong; I did think before I posted.

I have just moved in to a conventionally built modern house with stud walls. One of the fitted shelves is tearing the "heavy duty" plasterboard type Rawlplugs(tm) out of the plasterboard because the holes were drilled about 1mm too big (11mm when 9 or 10mm is actually needed). In fact it's a wonder that the screws were ever nipped up in the first place as I reckon the plugs have turned round and round.

The shelf is 10" deep and 2' wide and fixed by two T brackets where the long arm of the T bears the shelf and the short arm (about 4" long) mounted vertically on the wall has two screw holes. Maximum load will be about 10Kg including the weight of the shelf itself.

I want to keep the shelf in exactly the same location, so need to fill the holes and redrill them; I don't want to use spring loaded expanding toggle bolts so the question is, "fill them with what?"

Do expanding foam gap fillers permit drilling followed by load bearing such as with a snug fitting Rawlplug? If so, what type of Rawlplug? Plasterboard or "conventional brick type"? The bottles mention sanding, but not drilling, hence the question. One thing that I am aware of is that if I use such a product I need to leave room for further expansion as the foam cures as well as a water mist per the instructions.

Many thanks.

 

[Belle427]

is there a brick structure behind it?

 

[Widgets]

Yes; I don't know the correct term or product name to use, but a type of grey breeze block that drills beautifully easily compared to traditional coarse breeze blocks that cause the drill to jump and scatter until the bore proper has started to cut.

 

[sime10]

Thermolite blocks? hit the plug past the plasterboard and use a thicker screw

 

[^woody^]

I would use car body filler

 

[Widgets]

Thanks for the comments. Air gap is a good 3/4" so I'd rather not use a longer screw that can reach a plug pushed in to the Thermalite (thank you) blocks.

I don't have any car body filler but today found an unopened can of the expansion filler I first mentioned. Any comment on the likelihood of success if I use it, please? My idea is to fill in stages being careful not to use too much, and then dress with polyfller to get a good cosmetic finish.

 

[Belle427]

i dont think there is a suitable product to use for this,they just are not strong enough,fixing into the thermalite is the most suitable,or spring toggles,failing that throw the shelf in the bin

 

[Widgets]

Many thanks for all the comments; with job now done, here's the result as a courtesy and to help others with the same or similar problem. I came across some long, thin, Rawlplug "Hammer in" block fixings that looked like they'd work. Never seen before by me, I purchased a packet. Being much smaller o/d than the removed plugs and resultant gaping holes in the plasterboard, I did thus;

• 1 ) Filled gap with expansion filler (Polyfiller would have taken an age to set, even in thinish layers)
  2 ) Drilled through cured expansion filler and in to Thermalite blocks
  3 ) Hammered in fixings so the lipped front was flush with the plaster board outer face
  4 ) Removed screws from fixings and temporarily blocked resultant hole to prevent Polyfiller ingress
  5 ) Packed shallow area surrounding plug with Polyfiller, let it set, and sanded smooth
  6 ) Touched in with paint to match wall (matt white, so easy) and let dry
  7 ) Removed temporary blocks from Rawplugs
  8 ) Hung shelf by refitting screws and nipping up tight.

Absolutely rock solid.