This video has a wealth of information and helped me install these sheets on a greenhouse. But a note about the H-joiner strips. In spite of my best efforts I could not make them snap in and stay. It looked like you had to use a lot of force to really slam them in place. I'm not as much of a daredevil about climbing onto my greenhouse roof to put all my weight on them, and exerting enough sideways force on the vertical ones was nearly impossible. Using a rubber hammer in one spot jarred the whole strip and made it spring loose somewhere else. What worked a little better for me than pounding was to press the face of a 2-ft piece of 2x4 against the strip to force it down, then slide the 2x4 along and repeat. But once I got to the end of my reach and had to change positions, the thing would spring loose again. I was never able to get all the strips fully in place, and had no confidence they would stay there. So I ended up screwing the outer strips in place. I predrilled the holes, used round-headed screws with flat metal washers under them, and put a blob of silicone goop under each washer and on top of each screw. Hopefully that will hold them and keep out water. If I ever use this type of panel again I'm going directly to that method.
Thanks for your feedback :) A shame to hear about the H joiners. Were they ones you bought in the US? I haven't had that issue with the ones in New Zealand, but there are all sorts of different H snap joiners around the world. Good advice about screwing the top cap down if anyone runs into that issue.
Thanks for that, brilliant. I'm looking to roof a pergola and have taken some pointers from your video. Many thanks. Quick question though... could you have used wider sheets to cut down on the number of sheets such as the 1200mm (or even wider) you mention? 👍
Hi there, no worries :) Yes you can absolutely use wider sheets. I'd normally use 1220mm but I happened to have some 610mm that I needed to use. If you use 1220mm (or wider) you need rafters at around 600-650mm apart. So some of these will be in the middle of the sheet. In which case you use the Twinwall fasteners to fasten the sheet onto the rafter (drilling an expansion hole first). Hope that helps! Kurt.
A very useful video that will give me the confidence to replace my poly twinwall porch roof. The existing roof is 2m wide and 1m long with only outer supports. Do you think it would be better to add a middle support? Thanks again Colin
Glad it was helpful :) Yes you would need to add supports no further apart than 600mm (for 6mm Twinwall) or 800mm (for 8mm). Otherwise it will flex too much. Regards, Kurt.
Hi there, our H snap joiners are designed to be screwed through the bottom, into the rafter. Then you put the sheets on and then snap the top part of the H joiner on. If the sheets are 1200mm wide, they will also need to be screwed through the sheets into the rafter that goes under the middle of the sheet. More info here: twinwall.co.nz/ Thanks, Kurt.
Hi there, we don't recommend joining them end on end. It's better to use one full length of Twinwall. Otherwise you'll get water and debris in the joins and inside the flutes. Thanks, Kurt.
@ thank you so much for the fast reply. Do you recommend to also tape the length before adding on the H channel to connect two sheets together? or is the H channel enough to keep water and debris out?
No worries :) You don't need to tape the sides as long as it is cut parallel to the internal flutes. It's only the open flute ends that you need to tape.
I used polycarbonate shelf liners as windows for my horse trailer. Now it's been a few years and they have cracked from sun damage. Wondering if I should buy twinwall instead or would I be better with shelf liners?
Hi there, I think the issue with shelf liners is that they're designed for indoor use so don't have the UV protection required for outdoor use. So you'd be better off with Twinwall or another solid polycarbonate for outdoor (roofing) use. I hope that helps! Kurt.
Hi there, thanks for the vid, the spacings between the rafters you mention need to be 640mm, is this centre to centre, inside or outside dimension? Cheers
Hi there, no worries. It depends on the width of the sheet, and the inside width of the joiner. E.g. if your sheets are 610mm wide, and you allow a 30mm gap for the joiner, then you'd have 640mm spacings centre to centre. There's a diagram here that may help: sunnyside.co.nz/product/twinwall-polycarbonate-roofing/ Thanks, Kurt.
Hi i got glazing bar screw to timber put 100mm polycarbonate sheet but when i wont put cap on its not cliping this screw on this way. If polycarbonate sheet was 160mm wilby fine. Any ideas? Thanks
I'm looking to replace a clear corrugated pvc roof. The timbers are already installed but not to vertically every 4ft however there are horizontal latts going across so can the multiwall just be fitted onto the latts?
Hi there. Yes, generally it can be fitted directly on to the horizontal purlins, as long as the joiners that you're using are suitable for that. It should show in the installation instructions for your system whether it's ok to only be supported on the purlins (depending on how far apart they are - usually around 800mm 32in or so). Thanks, Kurt.
If I am using aluminum framing for 4x14 feet sheets (in the usa), do you have any recommendations of crossbar framing measurements? Would we need to cut the poly sheets down from 14 feet to 4x4 using H channels on all sides or is there a way to prevent the sag without cutting the 14 foot sheets down? My research says NOT to use silicone to adhere the poly to a rafter or support beam? Is this correct? If so, then we would have to cut them, correct? I am stuck and winter is coming. Please help!
HI there. I wouldn't recommend cutting them down, best to leave them as full sheets running the whole way down the roof. If you cut them down there's no real way to stop them leaking where the water runs. I'd recommend rafters at 2ft centers (600mm). That way you'll have a rafter running the center of the sheet supporting it (you can put screws through the sheet into this rafter), and a rafter on each edge that you can put the H channel joiner on to join the sheets. Alternatively, instead of the center rafter, you can put nogs/purlins running between the joining rafters. So these would be 90deg to you joining rafters. You could space them about 2-3ft apart. Don't use silicone as that can break down the polycarbonate, and will eventually work free anyway. Hope that helps! Kurt.
@@sunnysidenz OMG! THANK YOU FOR SUCH A QUICK AND FULL RESPONSE! Bless you a thousand times! I am not sure I understand the 'nog', but my husband and brother will! Wish you were close to me... I would hire you to do it! lmao! May life hold you safe and happy! You are definitely my 'sunnyside' today! Keep up the great videos! :-)
Can you share which tapes you would use for end and the other under flashing roof side? We are using u channels at one end, but not the end against facia, as the first installers did not do it, so now we have to use a tape. It is under flashing. I think it is a silver metallic type but can't find it again. Thx again!!
Thanks :) We actually supply the Twinwall, so if you're in New Zealand it can be purchased from sunnyside.co.nz. If you're not in New Zealand, if you search for Twinwall or Multiwall polycarbonate in your area you should find some suppliers. Thanks, Kurt.
Hi - I noticed you were kneeling on the panels. I was not aware they were strong enough to support a man’s weight. It won’t crush the channels in the panels to kneel on them while using the rubber mallet?
Hi there, good spotting. Ideally you wouldn't kneel on it, but because I've used it for some time I know how much weight I can put on it. Too much weight, especially on the point of the knee, and you will crush the channels. Best practice would be to use a drop sheet and plank on top if you need to put weight on it :)
Hi there, we don't recommend joining them end to end (which is what I think you mean). It's really hard to waterproof, and to stop debris and sediment from sitting on the lower sheet and making it's way back up into the flutes of the higher sheet. Thanks, Kurt.
Yes, any longer than a metre or so can be difficult. Generally you should cut the U channel to the width of the sheet only. If you really want the full 3m length you could try levering them on with a long piece of aluminium. Or using a rubber mallet (and a block of wood) to slowly push them on. Hope that helps! Kurt.
Hi there, generally you don't need to cover the ends of the joiners. However if the top end is exposed (e.g. not under a flashing) then you could put some sealant in there. Or if you're in a very dusty environment you could put sealant or tape on both ends of the joiner. Thanks, Kurt.
nothing wrong with your video, but this roof just gave me headache< we had so much issues with it that at the end we ripped it of and started the project all over with a simpler roof.
Hi there, you are correct, this is more difficult to install than corrugated polycarbonate. I've found the key thing is the joiners. One piece joiners (from other suppliers) are very difficult to use and sometimes impossible to get on. The two piece joiners are much easier. The second thing is being able to get the correct tapes to seal and waterproof the roof. I hope the simpler roof worked out ok for you. Thanks, Kurt.
This video has a wealth of information and helped me install these sheets on a greenhouse. But a note about the H-joiner strips. In spite of my best efforts I could not make them snap in and stay. It looked like you had to use a lot of force to really slam them in place. I'm not as much of a daredevil about climbing onto my greenhouse roof to put all my weight on them, and exerting enough sideways force on the vertical ones was nearly impossible. Using a rubber hammer in one spot jarred the whole strip and made it spring loose somewhere else. What worked a little better for me than pounding was to press the face of a 2-ft piece of 2x4 against the strip to force it down, then slide the 2x4 along and repeat. But once I got to the end of my reach and had to change positions, the thing would spring loose again. I was never able to get all the strips fully in place, and had no confidence they would stay there.
So I ended up screwing the outer strips in place. I predrilled the holes, used round-headed screws with flat metal washers under them, and put a blob of silicone goop under each washer and on top of each screw. Hopefully that will hold them and keep out water. If I ever use this type of panel again I'm going directly to that method.
Thanks for your feedback :) A shame to hear about the H joiners. Were they ones you bought in the US? I haven't had that issue with the ones in New Zealand, but there are all sorts of different H snap joiners around the world. Good advice about screwing the top cap down if anyone runs into that issue.
Thank you for putting this together.
You're welcome :)
That’s pure genius. To mention a rubber mallet, while banging it down with your hand.
FANTASTIC video! Lifesaver! Thanks mate!
Thanks for that, brilliant. I'm looking to roof a pergola and have taken some pointers from your video. Many thanks. Quick question though... could you have used wider sheets to cut down on the number of sheets such as the 1200mm (or even wider) you mention? 👍
Hi there, no worries :) Yes you can absolutely use wider sheets. I'd normally use 1220mm but I happened to have some 610mm that I needed to use. If you use 1220mm (or wider) you need rafters at around 600-650mm apart. So some of these will be in the middle of the sheet. In which case you use the Twinwall fasteners to fasten the sheet onto the rafter (drilling an expansion hole first). Hope that helps! Kurt.
A very useful video that will give me the confidence to replace my poly twinwall porch roof. The existing roof is 2m wide and 1m long with only outer supports. Do you think it would be better to add a middle support? Thanks again Colin
Glad it was helpful :) Yes you would need to add supports no further apart than 600mm (for 6mm Twinwall) or 800mm (for 8mm). Otherwise it will flex too much. Regards, Kurt.
Where did you put the screws into the roofing??? Everything I read says don't screw threw the H profiles.
Hi there, our H snap joiners are designed to be screwed through the bottom, into the rafter. Then you put the sheets on and then snap the top part of the H joiner on. If the sheets are 1200mm wide, they will also need to be screwed through the sheets into the rafter that goes under the middle of the sheet. More info here: twinwall.co.nz/ Thanks, Kurt.
If I want to make my polycarbonate longer, can I still use the h channel to connect them along the width side ?
Hi there, we don't recommend joining them end on end. It's better to use one full length of Twinwall. Otherwise you'll get water and debris in the joins and inside the flutes. Thanks, Kurt.
@ thank you so much for the fast reply. Do you recommend to also tape the length before adding on the H channel to connect two sheets together? or is the H channel enough to keep water and debris out?
No worries :) You don't need to tape the sides as long as it is cut parallel to the internal flutes. It's only the open flute ends that you need to tape.
I used polycarbonate shelf liners as windows for my horse trailer. Now it's been a few years and they have cracked from sun damage. Wondering if I should buy twinwall instead or would I be better with shelf liners?
Hi there, I think the issue with shelf liners is that they're designed for indoor use so don't have the UV protection required for outdoor use. So you'd be better off with Twinwall or another solid polycarbonate for outdoor (roofing) use. I hope that helps! Kurt.
Hi there, thanks for the vid, the spacings between the rafters you mention need to be 640mm, is this centre to centre, inside or outside dimension? Cheers
Hi there, no worries. It depends on the width of the sheet, and the inside width of the joiner. E.g. if your sheets are 610mm wide, and you allow a 30mm gap for the joiner, then you'd have 640mm spacings centre to centre. There's a diagram here that may help: sunnyside.co.nz/product/twinwall-polycarbonate-roofing/
Thanks, Kurt.
Hi i got glazing bar screw to timber put 100mm polycarbonate sheet but when i wont put cap on its not cliping this screw on this way. If polycarbonate sheet was 160mm wilby fine. Any ideas? Thanks
Hi there, thanks for your message. I'm not sure I understand what you mean. Could you please clarify? Regards, Kurt.
I'm looking to replace a clear corrugated pvc roof. The timbers are already installed but not to vertically every 4ft however there are horizontal latts going across so can the multiwall just be fitted onto the latts?
Hi there. Yes, generally it can be fitted directly on to the horizontal purlins, as long as the joiners that you're using are suitable for that. It should show in the installation instructions for your system whether it's ok to only be supported on the purlins (depending on how far apart they are - usually around 800mm 32in or so). Thanks, Kurt.
Great video 🙌
🔥💪Needed this to protect our tv on the ZeboZAP.
Love this video thank you!
If I am using aluminum framing for 4x14 feet sheets (in the usa), do you have any recommendations of crossbar framing measurements? Would we need to cut the poly sheets down from 14 feet to 4x4 using H channels on all sides or is there a way to prevent the sag without cutting the 14 foot sheets down? My research says NOT to use silicone to adhere the poly to a rafter or support beam? Is this correct? If so, then we would have to cut them, correct? I am stuck and winter is coming. Please help!
HI there. I wouldn't recommend cutting them down, best to leave them as full sheets running the whole way down the roof. If you cut them down there's no real way to stop them leaking where the water runs. I'd recommend rafters at 2ft centers (600mm). That way you'll have a rafter running the center of the sheet supporting it (you can put screws through the sheet into this rafter), and a rafter on each edge that you can put the H channel joiner on to join the sheets. Alternatively, instead of the center rafter, you can put nogs/purlins running between the joining rafters. So these would be 90deg to you joining rafters. You could space them about 2-3ft apart. Don't use silicone as that can break down the polycarbonate, and will eventually work free anyway. Hope that helps! Kurt.
@@sunnysidenz OMG! THANK YOU FOR SUCH A QUICK AND FULL RESPONSE! Bless you a thousand times! I am not sure I understand the 'nog', but my husband and brother will! Wish you were close to me... I would hire you to do it! lmao! May life hold you safe and happy! You are definitely my 'sunnyside' today! Keep up the great videos! :-)
No worries, happy to help and I hope it all goes well! Thanks :) Kurt.
Can you share which tapes you would use for end and the other under flashing roof side? We are using u channels at one end, but not the end against facia, as the first installers did not do it, so now we have to use a tape. It is under flashing. I think it is a silver metallic type but can't find it again.
Thx again!!
Oh wait ... think i found it in your video...lmao
Great video! Where did you buy your twin wall polycarbonate sheeting from?
Thanks :) We actually supply the Twinwall, so if you're in New Zealand it can be purchased from sunnyside.co.nz. If you're not in New Zealand, if you search for Twinwall or Multiwall polycarbonate in your area you should find some suppliers. Thanks, Kurt.
Hi - I noticed you were kneeling on the panels. I was not aware they were strong enough to support a man’s weight. It won’t crush the channels in the panels to kneel on them while using the rubber mallet?
Hi there, good spotting. Ideally you wouldn't kneel on it, but because I've used it for some time I know how much weight I can put on it. Too much weight, especially on the point of the knee, and you will crush the channels. Best practice would be to use a drop sheet and plank on top if you need to put weight on it :)
If need to use 2 lengths of 2.4m to use on a roof, how would you join the two together?
Hi there, we don't recommend joining them end to end (which is what I think you mean). It's really hard to waterproof, and to stop debris and sediment from sitting on the lower sheet and making it's way back up into the flutes of the higher sheet. Thanks, Kurt.
Could I use an H channel between the 2 pannels?
How do you add long 3m C sections , wont slide on too much friction.
Yes, any longer than a metre or so can be difficult. Generally you should cut the U channel to the width of the sheet only. If you really want the full 3m length you could try levering them on with a long piece of aluminium. Or using a rubber mallet (and a block of wood) to slowly push them on. Hope that helps! Kurt.
Very helpful , just a question how did cover on the joiner for water, dust we don’t have to use tape ?
Hi there, generally you don't need to cover the ends of the joiners. However if the top end is exposed (e.g. not under a flashing) then you could put some sealant in there. Or if you're in a very dusty environment you could put sealant or tape on both ends of the joiner. Thanks, Kurt.
Bravo
nothing wrong with your video, but this roof just gave me headache< we had so much issues with it that at the end we ripped it of and started the project all over with a simpler roof.
Hi there, you are correct, this is more difficult to install than corrugated polycarbonate. I've found the key thing is the joiners. One piece joiners (from other suppliers) are very difficult to use and sometimes impossible to get on. The two piece joiners are much easier. The second thing is being able to get the correct tapes to seal and waterproof the roof. I hope the simpler roof worked out ok for you. Thanks, Kurt.
wow this vid makes me embarrassed that the U.S. imposes imperial measurements on everyone. hahaha
The u.s love the gold old British measuring system 😂