Cheap Insulation/Plasterboard

xar

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Hi all,

Long time lurker, recent joiner. Just started to convert 2/3 of my detached double garage to a dedicated home cinema. Floor down and levelled, started to batten the walls now. Have been looking at insulating the walls with acoustic insulation and sound block type plasterboard. Room size is 18ft long, 9ft wide and need to cover the lot.

Anyone got some good recommendations for cost effective insulation and/or plasterboard? I have been looking at wickes/B&Q vs dedicated websites but all seems quite expensive. Looking to make use of the collective knowledge to save some green if I can.

Next up I will be pimping y'all for led light strip tips.

Cheers

Pete
 
Hi mate welcome to the club


You can use multipurpose inulation it cheap and effective.. Covered with sound board... Btw diy merchants tend to be cheaper as u can hagel the price
 
i would contact a few of the smaller builders merchants, like jewsons/ridgeons etc and play them off each other. when i insulated my rear extension, i used the new high density kingspan style insulation (but got a cheaper brand from ridgeons) and then used foil back plasterboard again from ridgeons.

this worked out about £2.50 a sheet of plasterboard cheaper than b&q and the insulation was also cheaper but cant remember by how much..
 
That's great. Thanks guys. Will try those ideas. Wife doesn't know what I am up to yet so if I can keep it cheap that will help...! ;-)
 
Do you just want to insulate the garage, or soundproof it as well? They require similar but different approaches depending on what you want to achieve. For instance, battening onto the walls isn't ideal if you want to soundproof.

Gary
 
Hi Gary - looking to soundproof as well. I have started one wall and have secured it to the floor and existing roof beams, but the vertical battens are a few mm off the wall itself. The garage wall is double skin but not insulated. The garage is also detached from the house and any neighbours.
 
Steer clear of B&Q for anything bigger than a pot of paint, they are hideously expensive, example...

On my 16:9 cinema project I needed some plastic trunking, the self adhesive stuff, B&Q price was about £5.99 per length, Screwfix price was about £1.30 per length and i picked it up so no delivery cost.

Timber is very £££ in B&Q too.

Shop around. ;)
 
Steer clear of B&Q for anything bigger than a pot of paint, they are hideously expensive, example...

On my 16:9 cinema project I needed some plastic trunking, the self adhesive stuff, B&Q price was about £5.99 per length, Screwfix price was about £1.30 per length and i picked it up so no delivery cost.

Timber is very £££ in B&Q too.

Shop around. ;)

which is just nuts considering they are both owned by the same parent company.
Screwfix is definitely cheaper, and easier (like argos) than B&Q. Wickes trumps b&q for staff knowledge if you need a bit of help. Also cheaper for some things.
I regularly make a trip to all 3, its a pita.
 
Hi Gary - looking to soundproof as well. I have started one wall and have secured it to the floor and existing roof beams, but the vertical battens are a few mm off the wall itself. The garage wall is double skin but not insulated. The garage is also detached from the house and any neighbours.

If the vertical battens aren't touching the existing wall, that should help prevent any vibrations from sound transferring directly to the existing wall. Vibrations travel through what they touch, so isolation is a good thing. An inch is usually a good guide for the gap.

Ideally you'd us 4 x 2 wood, fill with rockwool insulation, then finish with two layers of plasterboard, the second layer overlapping the seams of the first. Do the same with the new ceiling (insulation and two layers of PB). Seal all edges/gaps with silicon. Anything is better than nothing though. With external walls, you may need a vapour barrier between the rockwool and PB - check building regs etc for guidance.

Sound isolation is not just for stopping sound from getting it, it's also useful for preventing sounds getting in. The lower the noise floor in the room the better.

Gary
 
Thanks guys. I have discovered the B&Q pricing issue after buying the king span flooring insulation. Was painful. Never again.

In terms of double plasterboarding, can I just use regular board or should it be the sound bloc style most places seem to sell? Or one of each? Am trying to keep the costs down if can.
 
Regular PB is fine and cost effective - half inch or thicker will do.

Gary
 
sorry to sort of butt in but its something i don't understand and it is relevant: If you have your new wall separated from the wall by an inch but connected to the floor/ceiling then how do you prevent the sound going up/down via the battens? Or does it tend to be less due to a reduced contact area?
Do you suspend a new ceiling with a similar gap? Don't you need some fairly chunky beams to support the plasterboard hanging on it (for a ceiling) and thus lose quite a lot of room height?

Is there a good diagram of a good way of doing it as i think i'd understand that better.
 
i think you can put a foam isolator on the bottom or something, more to absorb the vibrations than isolate?

i might have made that up though...
 
By leaving a gap, you reduce the contact area, so the sound only has the top and bottom to go through - as a percentage compared to the entire wall mounted on batons that touch the existing wall, its greatly reduced. Batons on the wall will work too, but not as well due to the extra transfer area.

You're right about the transfer via the top and bottom. As E-com says, you can further reduce that by adding rubber or foam at the top and bottom footer and header plates. The rockwool reduces sound transfer because when sound hits something and changes direction, it loses energy by giving of heat, so the wall gets a bit warmer. The plasterboard is mass, and that helps to absorb bass IIRC, but that is the hardest thing to completely isolate due to the length of the bass waves.

Ideally, to prevent the 'flanking' sound travelling up and down via the header/footer plates of the wall construction, you build a new floor first of all. You isolate that from the existing floor using rubber matting or proprietary isolation supports for new floor beams, and build a new floor, making sure none of it touches the existing walls. Then you build the new walls (that don't touch the existing walls or ceiling), then hang your new ceiling joists on that. Finish with rockwool and plasterboard with silicon and that's almost a 'room within a room' which is the best way to isolate a room from the rest of the house.

Doorways are a bit more complicated :)

It all depends on how far you want to go, and how much cost you want to incur. If you want to further improve you wall/ceiling soundproofing, you would use GreenGlue between each layer of plasterboard.

Another option to two layers of plasterboard, is to use OSB or similar as your first layer, and then PB as your second. The reason you'd use OSB is because it allows you to screw things into it through the PB, and you aren't limited to where the batons are. It gives you greater flexibility so you can build soffits/whatever wherever you like.

Gary
 
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