ASHP on flat roof

[nicolab]

Hello,

 

We are planning to get an ASHP installed on the flat roof of our 1960s terraced house. Due to the layout of the house, it would be tricky to put the heat pump in the garden and would involve lots of boxing out, whereas on the roof the pipework can drop straight down into the first floor airing cupboard.

 

A structural engineer thinks it's fine to place it on the roof, as long as it sits on top of the one loadbearing internal wall that goes down to ground level.

 

We are getting the roof externally insulated and new torch-on felt. The roofing company are reluctant to give us a warranty for the roof if we put a heat pump up there - even if we try to co-ordinate the install so they can supervise it.

 

Questions:

 

- Have other people put a heat pump on a 1960s or similar flat roof without any additional strengthening work?

- Does the heat pump need to fix through the insulation directly to the plywood?

- Any tips on making it work with the roof warranty?

- Somebody suggested that it's no good using anti-vibration mounts if they are fixed through to the timber roof structure - i.e. the vibrations will carry through to the house. Is this true? Any thoughts/experience on this?

 

Thank you!

[Carrerahill]

11 minutes ago, nicolab said:

Hello,

 

We are planning to get an ASHP installed on the flat roof of our 1960s terraced house. Due to the layout of the house, it would be tricky to put the heat pump in the garden and would involve lots of boxing out, whereas on the roof the pipework can drop straight down into the first floor airing cupboard.

 

A structural engineer thinks it's fine to place it on the roof, as long as it sits on top of the one loadbearing internal wall that goes down to ground level.

 

We are getting the roof externally insulated and new torch-on felt. The roofing company are reluctant to give us a warranty for the roof if we put a heat pump up there - even if we try to co-ordinate the install so they can supervise it.

 

Questions:

 

- Have other people put a heat pump on a 1960s or similar flat roof without any additional strengthening work?

- Does the heat pump need to fix through the insulation directly to the plywood?

- Any tips on making it work with the roof warranty?

- Somebody suggested that it's no good using anti-vibration mounts if they are fixed through to the timber roof structure - i.e. the vibrations will carry through to the house. Is this true? Any thoughts/experience on this?

 

Thank you!

Speak to a commercial roofer, sounds like your roofer is a bit more, domestic, and not used to this, common for commercial roofs to be covered in plant.

 

Bauder recently did a roof on a project I was involved in, between my mechanical colleague and I we designed loads of stuff onto the roof - PV, air handling units, AC etc. and as long as the contractors used the approved methods and materials the whole thing was given a 20 year warranty! 

Edited June 19, 2023 by Carrerahill