EPDM roof for car port - queries

[Sam Maguire]

Filling in space between house and boundary wall with a carport type roof 3.6m wide x 5.5m long. Timber joists on wall plate / ledger either side and open ends.
We plan to expose the joists and deck underside and therefore thinking of 110mm x 18mm treated tg&v boards as we prefer look of them to OSB.
1. Any issue with laying EPDM on these boards ? Nails can be concealed or well driven. Flat head nails might be better ? Any additional precautions ?

2. As joists will be sitting on hangers each side, I trust we need to allow some room for expansion between end of joists and wall plate / ledger (span = 3.65m) say 5mm each end ?

3. I will be chasing in either lead or other type flashing into house and over EPDM. As only a car port I don't want to remove dry dash to expose block work for flashing - is there anything else I could fix to the dry dash to bond the EPDM to ? 1mm gauge aluminium or thin ply ? Seal top and dress lead over ?

Hope ye can help. This is a terrific forum.

 

[^woody^]

Lost head nails may be better as they will sit lower or flusher than flat, and won't cause the timber surface to dip around them. But check what the EPDM manufacturer says.

Joists don't expand in the length, so no allowance required.

There are self adhesive flashings available, but any render should be relatively smooth and firm.

 

[Vinty]

Filling in space between house and boundary wall with a carport type roof 3.6m wide x 5.5m long. Timber joists on wall plate / ledger either side and open ends.
We plan to expose the joists and deck underside and therefore thinking of 110mm x 18mm treated tg&v boards as we prefer look of them to OSB.
1. Any issue with laying EPDM on these boards ? Nails can be concealed or well driven. Flat head nails might be better ? Any additional precautions ?

2. As joists will be sitting on hangers each side, I trust we need to allow some room for expansion between end of joists and wall plate / ledger (span = 3.65m) say 5mm each end ?

3. I will be chasing in either lead or other type flashing into house and over EPDM. As only a car port I don't want to remove dry dash to expose block work for flashing - is there anything else I could fix to the dry dash to bond the EPDM to ? 1mm gauge aluminium or thin ply ? Seal top and dress lead over ?

Hope ye can help. This is a terrific forum.

Filling in space between house and boundary wall with a carport type roof 3.6m wide x 5.5m long. Timber joists on wall plate / ledger either side and open ends.
We plan to expose the joists and deck underside and therefore thinking of 110mm x 18mm treated tg&v boards as we prefer look of them to OSB.
1. Any issue with laying EPDM on these boards ? Nails can be concealed or well driven. Flat head nails might be better ? Any additional precautions ?

2. As joists will be sitting on hangers each side, I trust we need to allow some room for expansion between end of joists and wall plate / ledger (span = 3.65m) say 5mm each end ?

3. I will be chasing in either lead or other type flashing into house and over EPDM. As only a car port I don't want to remove dry dash to expose block work for flashing - is there anything else I could fix to the dry dash to bond the EPDM to ? 1mm gauge aluminium or thin ply ? Seal top and dress lead over ?

Hope ye can help. This is a terrific forum.

You can use firestone termination bar, which is designed for use with epdm.

You use the sealent to seal any gaps between the bar and the wall.
https://www.rubba-seal.co.uk/product/firestone-water-block-sealant/

 

[Sam Maguire]

Thanks for those helpful and informative replies. I am waiting on reply from roofing supplier.