So we havent anything down upstairs yet but confused as to what might work best. So we have 13mm in total for an underlay and floor. We are getting impact noise (ecojoists and rockwool inside) so would like something to dull it. A dog means carpet will not work. We were thinking of laminate but which one and for what underlay? Ideally around 27db. Anyone solved this? Local flooring shop suggested Black diamond 5mm, looked it up all i can see is this by a company in scotland

Edited Wednesday at 09:232 days by CalvinHobbes

Bump

With 13mm total to play with you're fairly limited, so it's worth being realistic about what the underlay alone can do. Footfall noise through a joisted floor mostly travels through the structure, so a good underlay helps but the bigger gains are usually elsewhere.

A few things I'd look at:

Black Diamond is a dense rubber type acoustic underlay, and a dense 5mm one is about as good as you'll get at that thickness. Check the laminate manufacturer allows a 5mm underlay though, as many limit it to 2 or 3mm and anything too soft lets the click joints flex and creak over time.

When comparing dB figures, make sure they're the same test (impact sound improvement, often shown as ΔLw). Different makers quote different numbers and it's easy to compare apples with pears.

Within 13mm you're roughly at 8mm laminate on 5mm underlay, or 10mm on 3mm. Heavier, denser boards, or a laminate with a bonded acoustic backing, usually sound less hollow than thin cheap ones.

If the ceiling below isn't finished yet, resilient bars or acoustic hangers with a dense acoustic plasterboard will do far more for footfall than any underlay, and the Rockwool between the joists then earns its keep.

Leave the expansion gap all round and don't let the skirting pinch the floor, otherwise you bridge the sound straight into the walls. Rugs in the main walkways help too, dog permitting.

Why only 13mm? Easy to trim off 5mm on your doors. Then you can go with 5mm wood fibre underlay and 12mm laminate.

An alternative is LVT.