Floor insulation and current regs

[DumbBlonde5]

We are having a loft conversion. Both the building control plans and our quote stated we wanted rockwool 100mm under the new floor. Instead our builder has just reused our old loft insulation (very old and patchy) and added a tiny amount of Knauf Loft 44 in places. Floor is now down and walls plastered.

Obviously we are not happy as we specified rockwool for fire and acoustic reasons. Building control came out for insulation inspection and didn't seem to notice this.

What are the implications? Do regs specify acoustic insulation? Or new insulation etc? How bad is it if builder has to pull up floor and redo? This won't be possible in ensuite as karndean floor going down in 2 days.

 

[JP_]

PITA when builders don't do as asked. Acoustic insulation is always a good idea. Get somebody (not a builder!) to walk around upstairs and listen from below - how does it sound. Put the TV on, can it be heard clearly in a bedroom below? Flush the toilet, is it noisy? If no to all, then you'll probably be OK, especially once carpets with underlay go down.

Otherwise, they'll need to lift the floor and do as told, and the Karndean fitter will have to come back another day.

 

[RonnyRaygun]

I don’t think building control will care how sound travels between floors of a single dwelling.

Not sure about the fire risk, but I guess there’s also risk of ignition from an electrical fire from cables in the floor void.

Either way, if the builder hasn’t followed the plans (that I assume he priced the job from), then you are obviously within your rights to ask him to put it right

 

[DumbBlonde5]

PITA when builders don't do as asked. Acoustic insulation is always a good idea. Get somebody (not a builder!) to walk around upstairs and listen from below - how does it sound. Put the TV on, can it be heard clearly in a bedroom below? Flush the toilet, is it noisy? If no to all, then you'll probably be OK, especially once carpets with underlay go down.

Otherwise, they'll need to lift the floor and do as told, and the Karndean fitter will have to come back another day.

Standing in the loft I can hear conversations on the ground floor which is why I started to wonder about what should have been done. Trying to work out if we could leave Karndean as ensuite is above main bathroom so not to delay and get him to redo rest of it. Or even if it's just a sound issue (not thermal or fire risk) then whether to try and counter with flooring. We need the space urgently due to a disabled child so trying to figure out best solution. Also suspect builder would walk off job if we push too hard and we'd struggle to get another builder to finish.

 

[DumbBlonde5]

I don’t think building control will care how sound travels between floors of a single dwelling.

Not sure about the fire risk, but I guess there’s also risk of ignition from an electrical fire from cables in the floor void.

Either way, if the builder hasn’t followed the plans (that I assume he priced the job from), then you are obviously within your rights to ask him to put it right

He hasn't followed plans fully and has made his own alterations usually without telling us until it's done.

The stuff he's added a little of is still fire retardant but not sure about the risk with the original stuff as not sure what it was/how old etc

 

[mrrusty]

Personally I think you won't succeed arguing regs, however, if the contract and quote says rockwool and they didn't, you can argue contractual reasons. If you haven't paid, you could ask them to rectify and/or if they refuse get someone else to do it and go after them for the additional cost. However, hassle over benefit is probably marginal - I doubt rockwool over glass wool loft insulation will make that much difference, although rockwool is denser and better to an extent for sound insulation.

At the very least cost the rockwool needed and deduct as they didn't do it.

 

[DumbBlonde5]

 

[DumbBlonde5]

 

[DumbBlonde5]

 

[DumbBlonde5]

 

[DumbBlonde5]

Photos of an exposed area. Probably less insulation in other parts as that's our old stuff.

 

[mrrusty]

Not great! That's worse than I envisaged and basically doing nothing. As above, I don't think the regs will help you with an intermediate floor, but talk to your BC, but you can def. fight on the contractual agreement.

 

[Harry Bloomfield]

At the very least cost the rockwool needed and deduct as they didn't do it.

Plus cost of disposal of the old material (a skip).

 

[^woody^]

How bad is it if builder has to pull up floor and redo

Not as bad as if a fire ripped through the floor, and then the insurance don't pay out as you failed to declare it, or the inspector wants it rectified later.

 

[^woody^]

And check your spec, as normally insulation for fire is suspended in wire mesh, not just plonked on the ceiling board below.