How to retrofit underfloor insulation?

[lm4]

Hey all,

I am hoping to retrofit our townhouse with underfloor insulation as a summer project, and had a couple of questions after having a look underneath the house today.

1. The floor joists we have are a bit of a mess in terms of spacing (putting it nicely). There are various sections where joists run parallel for a couple of metres only spaced by 10mm or so, and other areas where joists intersect into the gap where the insulation should sit (attached photos). What would be the best method and/or product to approach this? The polystyrene insulation panels only seem to be able to be cut nicely at the edges, and I imagine Earthwool might be hard to cut a chunk out of in the centre...

2. Our bathroom is on a concrete floor, and some more complicated joist/piping work near it - should this area also have insulation installed underneath it for best effect or is not worth the effort for this area?

I have attached some photos underneath to hopefully make my questions a little clearer.

Any advice would be much appreciated! Cheers

Joist overlapping into insulation spaceSmall gap between joists and concrete floor

[JacobZ]

Hi @Chris1256,

A warm welcome to the Bunnings Workshop community, it is fantastic to have you join us.

It's great to see @lm4's post has inspired you to get started planning a similar project.

I notice you've made a post of your own, so I will jump over and help you out there.

Jacob

[Chris1256]

Was there a completed photo after this was all finished?

I am thinking of insulating and fireproofing under my house.

[JacobZ]

Hi @Chris1256,

Allow me to tag @lm4 so they are notified of your question.

Hopefully they will be able to assist with some photos shortly.

Jacob

[lm4]

Hi @Chris1256 

Unfortunately we haven’t gotten around to doing this yet. Good luck! 

Cheers