1200 gauge damp proof membrane size problem on conservatory?

[HAYSTACK]

Hi. Wonder if anyone can help with a question regarding my DIY conservatory build.

I have just blinded off the hardcore with building sand and am ready to lay the blue membrane before doing the floor (3 sections of 12cm thick concrete with metal strengthening grid).

Problem is, the blue membrane sheeting only seems to come in 4m width. My conservatory is 5.5m wide x 4m out. The sheet, with fold ups and over inner cavity is more than 4m.

Can I join 2 pieces together with gaffer or something? Seems ridiculous there isn't wider lenghs available.

Thanks for any advice!

 

[freddiemercurystwin]

Tape it both sides with some of this: http://www.screwfix.com/p/duck-original-cloth-tape-50-mesh-black-50mm-x-25m/41045 Don't be shy with the lap.

Many would argue the weight of the concrete will provide a seal. Its not practical or necessary to make roll widths any bigger, joining is fine.

 

[HAYSTACK]

Thank you. I think I will make the join neared the house end. The roll is 15m long, so I could probably do 2 layers to be sure.

Cheers

 

[freddiemercurystwin]

2 layers? Why bother? Understand its little extra effort and you have all the gear anyway but still overkill.

 

[HAYSTACK]

Yeah, your probably right lol. I'll just do the one and keep the roll in the shed for any future projects.

Thanks again!