Overhang issue

[new eco home]

Hi,

 

We are at design stage of our project. I am new to self build and any construction related , so please ignore me if I ask any silly questions

 

Could you please advice is it possible to achieve overhang of 200mm on first floor by using external insulation. As per plans, ground floor external walls line up with first floor. But we have a 180mm overhang on first floor which we would like to achieve by going external 180mm wood fibre insulation.

 

Is 140mm stud enough to carry loads on first floor or else do we need to go for either 180mm or 240mm timber studs

 

Could you please let us know any pros and cons with this approach. Are there any thermal bridges occur based below wall build up. we would like to use as much less steel to avoid any cold bridged

 

Please advice for any special fixings or anything to worry about at design stage

 

 

 

MarkedPlans.pdf

Edited October 9, 2019 by new eco home
Removed files

[Russell griffiths]

Do you want, or need the extra insulation upstairs?

if not why not just get a frame company to build a frame that steps out

seems an expensive solution to the problem, and a pain to fit,  250mm fixings cor blimey. 

[new eco home]

Hi @Russell griffiths, thank you. Yes, your are right. Best option is to get frame company to do it. Do we need to worry about any cold bridges when frame steps out on first floor.

[Russell griffiths]

Not if you design them out 

[new eco home]

Hopefully Frame company can sort this out 

[ProDave]

Which render system are you planning on the wood fibre board?

[new eco home]

Hi @ProDave, we are thinking of either Sto, K-Rend, Weberend or SAS but not yet decided. We are still negotiating how best to build overhang rather than using either external wood fibre or  cladding support brackets(rails). Just comparing different cost options and their implications onsite. Hopefully frame company can do it without any cold bridges to avoid unnecessary complicated issues on site. Render company says they wont do or guarantee any cladding brackets that support 200mm overhang

[PeterW]

Reading this, your overhang is purely an architectural decorative feature, is that correct ..???

[new eco home]

Yes, you are right @PeterW......its there only for aesthetic purpose.....unnecessary expense and causing delays....but it's too late now ?.I should not have gone for it from the beginning

[Russell griffiths]

1 hour ago, new eco home said:

Yes, you are right @PeterW......its there only for aesthetic purpose.....unnecessary expense and causing delays....but it's too late now ?.I should not have gone for it from the beginning

In that case, build the timber frame straight up, and get an additional Larson truss type arrangement screwed on the outside, render board and render. 

 

[Russell griffiths]

Like the pic but just upstairs, will need a good detail around the windows, but not hard.