Can expanding foam fill old gas heating ducts in the floor?

[diohoh]

Do you think this would work. I am having new carpet laid 

[JacobZ]

Hi @diohoh,

A warm welcome to the Bunnings Workshop community and thank you for your question.

Assuming the gas heating ducts have been decommissioned, then yes, expanding foam will work to fill the heating ducts in the floor.

Let me know if you have any further questions.

Jacob

[diohoh]

Thanks for replying Jacob. So Bunnings sell the cans that have guns attached to them. 

[JacobZ]

Hi @diohoh,

There are cans that have a tube attached to them that are perfect for smaller projects. This Sika 500ml Boom Expanding Foam Filler is an example of one that won't require a gun.

We do sell the Sika Sikaboom 100 Foam Dispenser Guns, but it wouldn't be necessary if you were only doing a small job.

Let me know if you have any further questions.

Jacob

[MitchellMc]

Hi @diohoh,

I just wanted to touch on whether these duct openings will be walked over afterwards? If so, you'll need to reinstate the flooring in that area as expanding foam compresses under weight and you'll end up with a sunken section. If you can provide some images we can advise on how to repair the floor there. Let me know if you need a hand uploading images.

Mitchell

[diohoh]

Thanks Jacob,

I have ordered the refill can along with the gun and the cleaner. I have at least 8. I’m thinking I will do it in two stages. Wish me luck 

[diohoh]

Thanks Mitchell for your advice. They are all located around the walls. 

[JacobZ]

Hi @diohoh,

If you are confident the ducts are out of commission and they won't be walked on, then you should be fine to proceed.

Let us know if there is anything else we can assist with.

Jacob

[diohoh]

Hi Jacob, I have had another suggestion from a friend which is to place some thin metal pieces over top of the cavities before the underlay and carpet is laid. As I’ve already bought the expanding foam I thought I’d go ahead with that first and then after I trim it, I’ll put the metal pieces on top. 

[JacobZ]

Hi @diohoh,

Do you have some photos of the ducts?

Adding thin metal covers sounds like a good idea, but without seeing them, it would be hard for us to give you any advice on how to go about it.

Let me know if you need a hand uploading images.

Jacob