Wooden Cladding and insulation - your help!

[luhardi48]

We have a very old house (circa 1550) which has had vast amounts of work in raising it to a very good state of repair. We are now down to the final few jobs, one of which is to replace the wooden cladding on a portion of the rear of the house. I am after some advice to help complete the job.

Currently the wooden cladding in-situ is to be completely removed and replaced with new wood which will be primed and painted (already have the paint). The cladding is located on the first floor and surrounds what is the bathroom, running bottom to the top where the roof meets. Whilst we are at it I would like to insulate behind the cladding using something like rockwool slabs. There are some assumptions that beneath the cladding is a sound structure with vertical support which can be easily insulated between. Of course this might not be the case however we are always optimistic!

I have a number of questions that i would like some advice/input upon:

1. What is the best wood to use for such a job? We are not keen on using Oak for obvious reasons. Looking for an natural looking wood that is hard-wearing.

2. What insulation product/specifications? Given that we are making some assumptions to the treats beneath the cladding what have you used or would you suggest to provide a good amount of insulation? I am leaning towards Rockwool slabs.

3. Anything else to consider? I am confident to do the job with the aid of scaffolding and some extra hands. What else should we consider? What other challenges or areas for consideration should be factored in?

4. Around the roof, where the cladding meets the pitch, this gaps between the rafters is open to the elements. Given that the house is very cold I would like to get reduce heat loss such as this. Is there a specific reason why there is gaps between the rafters? Can this be closed off using pieces of wood or similar with some air spaces (of sorts) installed?

I hope this makes sense. Thanks for reading and and input you can offer!

Best regards,

L

 

[AronSearle]

1. What are the obvious reasons for not using oak, cost? Try thermowood, decently treated pine (thermowood would be better).



Given the age of the building, you likely have cladding direct to the frame, with a bituminous backing paper. If you insulate between the studs, it would be highly recommend that the cladding is re-installed on battens to created a drained and vented cavity, this will mean some slight tweaks to window reveals etc.

(When you have no insulation, the heat loss through the wall helps keep it dry, and makes not having a cavity less of an issue).

It doesn't really matter what insulation you use, though if you use rigid foam make sure it is fitted properly, with expanding foam to fit any gaps from in-accurately cut panels (a given).

4. I assume that gap is to allow ventilation to the roof-space, so leave them. But using rigid insulation around the eaves in the roof will stop wind blowing through the insulation which affects it's performance.

 

[luhardi48]

Hi, thanks for your help. We are moving closer to getting this project kicked off. With regards to the batten spacing what do you recommend? We are going for 8" feather-edge boards.

thanks in advance!