How to replace insulation against brick veneer in internal laundry wall?

Jcasey

Hi There - I am seeking some advice on steps I need to take to replace insulation removed from my laundry wall. As you can see it is against the brick veneer so I am wondering if I need to put anything against the brick before insulating? What insulation do you recommend also?

Finally is insulation safe against the water pipes or should a separate insulation sleeve go over the pipes?

Thanks in advance

JC

EricL

Hello @Jcasey

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about insulation.

Looking at your photo, you’ve essentially got a pretty typical older brick veneer setup where the timber frame sits inside the brickwork with a small cavity in between, and that silver reflective wrap you can see is acting as a kind of sarking or moisture barrier. The good news is you generally don’t need to add anything new directly against the brick itself as long as that reflective foil is still mostly intact, because its job is already to help manage moisture and radiant heat. In most brick veneer walls, the insulation simply sits within the stud cavity and doesn’t get pushed hard up against the brick; leaving a slight air gap is actually beneficial for moisture control and thermal performance.

For the insulation itself, a standard wall batt is exactly what you want here, and something like Earthwool or similar polyester/fibreglass batts from Bunnings is perfectly suited. https://www.bunnings.com.au/bradford-r2-7-1160-x-570-x-90mm-3-8m2-gold-high-performance-wall-batts-5-pack_p0015108 or the https://www.bunnings.com.au/earthwool-r2-7-shd-soundshield-wall-batt-90mm-x-580mm-x-1160mm-6-7m-10-pack_p0810977 range you’ll find on the Bunnings site are common choices and designed specifically to friction-fit snugly between your studs without sagging. In a laundry, I’d lean slightly toward a higher density option like an R2.5 or R2.7 batt if your stud depth allows, as it gives you a bit better thermal and acoustic performance without complicating the install. The key is to cut them neatly so they fully fill each cavity without being compressed or leaving gaps, as proper fit is what makes insulation effective.

With regard to moisture, since this is a laundry, it’s worth making sure that foil wrap is continuous or patched where it’s torn, rather than adding a separate plastic vapour barrier inside the room, because you don’t want to trap moisture inside the wall. If sections of that foil are badly damaged, you can repair them with https://www.bunnings.com.au/ametalin-48mm-x-50m-insulation-ducting-tape_p0810227 or similar from the store to restore that protective layer rather than replacing everything.

For your pipes, insulation batts can safely sit around them and this is very common practice, but you do need to be a bit thoughtful about it. You don’t want to compress the batt tightly behind the pipe or leave big voids, so it’s usually best to split the batt and fit it around the pipe so it stays fluffy and continuous. If those are hot water lines, adding a proper foam pipe lagging over the pipe first is a really good idea because it improves efficiency and prevents heat loss, and it also helps avoid condensation issues on cold lines. Something simple like https://www.bunnings.com.au/k-flex-13mm-wall-x-13mm-i-d-1m-elastomeric-pipe-insulation-suits-1-2-pipe_p4920350 is exactly the sort of product you’ll find at Bunnings for this purpose. Once the pipe is sleeved, you can then place the wall insulation neatly around it.

Overall, this is a very achievable job. As long as you keep the insulation neatly fitted, maintain that reflective barrier behind, and avoid compressing the batts or trapping moisture, you’ll end up with a much better performing wall both thermally and in terms of condensation control.

Here is a handy guide that will help: https://www.bunnings.com.au/diy-advice/home-improvement/heating-and-cooling/how-to-insulate-walls

Please remember to wear personal protection such as long sleeve shirt, gloves, goggles and a mask.

If you need further assistance, please let us know.

Eric