The case of the missing plasterboard screws and the skimming conundrum

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I do 7 across a board and also leave the cut edge until the next board is up against it. I think the white book says 225mm spacing for screws.
 
I didn't strengthen the joists where the unbound ends were. Nothing I read before hand said to strength them.
 
The advice from BG was seasoned timber (tick) screwed into joists at unbound edge (tick) supported by noggings unless joist centers were less than 450mm for 12.5mm (no noggins required, tick).
 
3/4 tongue and groove boards, which they boarded out (don't know thickness), self levelled and then tiled. What is the problem that you are hinting at bubbles65.
 
Well the conversion is 20 years old so I'd expect that in that time any problem would have emerged.

The joists sit on the 1.5 brick thick walls via an internal wall which I am not sure is structural. Some of the joists were only 100mm tall near the eaves, these were overlayed with perpendicular 100mmx 50mm joists to make them match height wise with the 200mm tall joists and give additional support where needed. I imagine that this was done when the conversion was done.

The only change in the joists I saw was some twisting evident in a few, nothing that I won't expect from a converted 100 year old propery.
 
jgw1 said:
Well the conversion is 20 years old so I'd expect that in that time any problem would have emerged.

The joists sit on the 1.5 brick thick walls via an internal wall which I am not sure is structural. Some of the joists were only 100mm tall near the eaves, these were overlayed with perpendicular 100mmx 50mm joists to make them match height wise with the 200mm tall joists and give additional support where needed. I imagine that this was done when the conversion was done.

The only change in the joists I saw was some twisting evident in a few, nothing that I won't expect from a converted 100 year old propery.
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So effectively (structurally) these are 4" x 2" joists........I would get a structural engineer to take a look to be on the safe side - I'm betting he won't pass it as acceptable.
 
No there is no weight on the shorter joists, like I said the joists transition from 200mm to 100mm tall and someone has run joists perpendicular on the shorter joists to get to the same height. Had the place fully surveyed when we bought it and no problems and no recommendation to structurally survey the property.
 
But were they aware that you intended to apply a double layer of soundblock boards to the underside of the joists, hmmm?
 
DannyMac said:
Five screws across the width of a board is plenty.
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Possibly, but (for clout nails) I was told one every 6" (150mm) on ceilings and every 8 - 10" (200 - 250mm) on walls. I've never changed that since changing to screws, maybe it was because we used to always apply a good coat of bonding before skimming, so ceiling weight would have been much greater than one that only had a skim on them :RpS_thumbup:
 
I find it really difficult to figure out the false members from the stupid questions lately, to the point where I'm thinking of quiting the forum for good.
Newbie questions should be in their own section and if posts are from present members under different names then action needs to be taken. This forum is becoming a load of bollakks because of either stupid questions or false members, come on genuine mods do something about it.
 
Hope that's not aimed at me Andy :RpS_unsure:
I don't do fake members anymore mate :-)
Out of interest which dodgy members/posts are you referring too by the way?
Just so I can check em out like :RpS_thumbup:
 
essexandy said:
I find it really difficult to figure out the false members from the stupid questions lately, to the point where I'm thinking of quiting the forum for good.
Newbie questions should be in their own section and if posts are from present members under different names then action needs to be taken. This forum is becoming a load of bollakks because of either stupid questions or false members, come on genuine mods do something about it.
Click to expand...

I find it really difficult to figure out the stupid members from the fake questions lately, to the point where I'm thinking of letting EssexAndy quit the forum for good, so come on genuine mods do something about it (whoever they are).

Just spoke to her she said "see ya later" xxxxxxx
 
I did a quick calculation and the double layer of soundshield added 150Kg compared to the equivalent regular knauf board. Translates to an additional 8Kg per m2. Not that worried about that extra weight on the joists.
 
Going off the beaten track here. But could you have considered a full fill of acoustic roll between joists, resiliant bar,and one layer of 15mm SB. This would have reduced your ceiling load and probably given a better airbourne sound loss figure. .Although I use the word probably,as the dB figures would have to be qualified.
 
Hi Mark,

I laid 100mm acoustic rockwool between the joists. I emailed GP and asked whether resilient bar and 15mm sound bloc or 15mm + 12.5mm soundbloc would be the better choice. They said that the latter would be better for impact noise IIRC.

The decider was that there are fitted wardrobes in the room that I needed to take into account of. The 15mm + 12.5mm option was roughly the same height as what I removed (it was 30mm deep in places but crucially not where the wardrobes were) whereas the resilient bar is 15mm deep so would perform worse and not fit in above the robes.
 
Hey all, new to the forum and I was just wondering why you rang BG when you're fixing Knauf board? Why not ring Knauf?
 
hah! I ordered BG sound bloc and did all the research with their online guides and sent off a few questions to their support guys. But the online retailer delivered Knauf, they are very similar products so I didn't send it back. That's just what turned up on the day.
 
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