Steel / timber frame expansion foam

[John_1919]

Progressing conversion of a steel portal frame barn to domestic use. Roof is Trisomet insulated composite panels supported by steel frame via steel purlins. Walls are infill timber frame. Due to expansion / contraction of timber with moisture content, walls are not structurally attached to roof.

Does anybody have any suggestions for suitably approved [preferably BBA approved] foam filler for the red in sketch below - roughly wedge shaped 100mm X 50mm
x length of wall

I assume normal expanding foam will crack over time

 

[freddiemercurystwin]

Is this just for air tightness or fire too? I don't think you'll find something designed specifically for that task so getting one with a BBA cert seems unlikely IMO. Perhaps something like https://www.newtonwaterproofing.co....sealing/non-absorbent-expansion-joint-filler/ would be suitable. You or your designer designer would need to determine how much expansion/contraction is likely and see if the chosen product can cope with it whilst retaining a seal.

 

[John_1919]

Just found this

https://www.buildingdesignindex.co.uk/category/4-11235/type/13/Movement-joint-seals/Products/
which has some interesting options particularly

https://www.illbruck.com/en-gb/products-systems/product-finder/tp610-ng-impregnated-sealing-tape/
and

TP450 NG Compriband Timber Max | illbruck UK

TP450 NG is a soft and flexible open cell polyurethane foam, impregnated with an acrylic based, UV stabilised resin. It provides a weather tight seal against the most severe combinations of wind & rain.

www.illbruck.com

Expensive and probably overkill but I think either will do the job provided I can install them before they expand out of control !

Anybody had any experience of using them or anything similar ?