Insulating my bathroom - how to go about it?

[ICanDoItWell]

I have a 1963 concrete no fines mid terrace and I would like to insulate the internal bathroom wall to help reduce condensation which forms while showering and to increase the warmth in the room. This wall is the front wall of the house lying in a South East direction.

I am considering using some insulation boards with a final plasterboard and vapour barrier and tiling using multiple boards up to a total of 85-90mm. The current bath of 1700mm which has the taps/plug hole on the front wall and currently just fits across the party wall would need to be replaced with a 1600mm bath after fitting the insulation.

• See picture below which sums this part up:
  The bath waste leaves via a 1.5" waste pipe which travels just above the floor of the bathroom across the front wall and through a block internal wall which is supported on the floor boards and then goes into the toilet waste pipe which goes through the floor of the toilet. The house soil waste pipe looks like a galvanised cast iron pipe with welded toilet and bath/basin waste to it which I don't think could be altered without major work and cost that I don't really want. The soil waste pipe vents through the roof. There are also two water pipes 22mm & 15mm just above this bath/basin waste pipe which will need altering to move the basin onto the adjoining internal wall.

The issue I have and what I want some advice on are the pipes that travel along the front internal wall and what I can do about them with regard to insulation? Is there any way to insulate above these pipes? Box them in? Insulate the pipes?

I can't really insulate to the floor because of them so what can I do? One of the pipes is hot water.

How could I support all that insulation because there is no support from the floor as it will have tiles on it and plasterboard?

I hope someone can give advice because I am about to alter my radiators and need to know what radiator heat output I will need when I purchase one for the bathroom. This is holding up the heating alteration because I don't want to keep draining my system.

 

[ICanDoItWell]

Here is a plan view of the bathroom which makes it easier to picture where everything is. It's not to scale!

Untitled

• ICanDoItWell
• 20 Nov 2010
• 1

Some help with this will be appreciated because I must order the remaining 2 radiators that I need on Monday.

 

[RedHerring2]

Can you box in the pipes? Any insulation will then be supported by the box section. Ensure that the front face of the box can be removed for access to the pipes. The box section could be the same width as the final insulation, plasterboard and tiles.
There's no reason why you can't insulate the 15mm &/or the 22mm pipes.
No need to insulate the waste pipe. The water will not freeze on it's way out.

I fail to understand why this is holding you up ordering or fixing the radiator.

 

[ICanDoItWell]

Can you box in the pipes? Any insulation will then be supported by the box section. Ensure that the front face of the box can be removed for access to the pipes. The box section could be the same width as the final insulation, plasterboard and tiles.
There's no reason why you can't insulate the 15mm &/or the 22mm pipes.
No need to insulate the waste pipe. The water will not freeze on it's way out.

Thanks for the reply. I could box in the pipes but I wonder if doing so will make if difficult to create a seal and preventing condensation and dampness getting behind the insulation panels. That is if the panels are attached via dot and dab. I don't want mould growth behind it and it being a bathroom with very high humidity levels, it's perfect conditions for mould growth.

Insulating the water pipes, the hot pipe especially should help prevent condensation forming.

Ideally a mechanical fixing would be used but fixing anything to no fines concrete is extremely difficult because fixings just fall out of it.

I fail to understand why this is holding you up ordering or fixing the radiator.

Because with the wall uninsulated the radiator size and style chosen will be different to what it would be if the wall is insulated.

I have been considering a towel rail but they put out a lot less heat and chrome in particular have quite low heat outputs. Stainless steel which have better heat output I cannot justify the extra cost.

A standard panel radiator with convector is the other option and more suitable if there is no insulation. These walls lose massive amounts of heat. The U value is about 2.5, the worst type of property for heat loss.

 

[chapeau]

... help reduce condensation which forms while showering...

If you remove the water it cannot condense, have you got an extractor fan?