Sealant for twinwall polycarb please

[Bertie Doe]

I'm planning to build a coldframe. A neighbour on the next allotment built one from twinwall but used Gaff or Duck tape to seal the ends.

After a short while, the water got in, followed by algae. I've been given 3 sheets of 8' x 2' poly similar to this :-

I'd like to inject say, an inch waterproof, fungi-proof sealant into the ends. I'm not worried about looks, it just has to provide a permanent seal to keep water out . Can anyone recommend some brands please. TIA.

[David Lang]

Have a look here - scroll down;

[Bertie Doe]

Thanks Dave the Polycarbonate Sheet End Closure White at £1.91 each looks good but these are for 16mm sheets. I'll try and google up some 10mm at a good price,

[Huge]

Where are you?

We have two you can have. A large twinwall one and a small glass one.

[Bertie Doe]

Very kind of you Huge, I'm in SE Cornwall but I already have the wood and 3 x 2.5m PC sheets.

However, you can't have too many coldframes :-)

[Chris Hogg]

When you seal the ends, make sure you do it outside on a cold dry day. That way you trap less humidity/moisture within the channels, so less chance of condensation in them in cold weather.

[Huge]

Ahh. North Beds. Never mind.

I do.

:o)

[Bertie Doe]

Ah! thanks Chris, hadn't thought of that. It'll happen next week, so plenty of cold days available. Not so sure if there'll be a dry day :-)

[David Lang]

I'm surprised they don't have 10mm?

[Brian-Gaff]

There used to be end cheek pieces for this which were glued in with a kind of cement, or glue, however when I last wanted some of these the profile I had on my sheets was no longer made.

I remember some RTV silicone stuff that one could use for this but in the end the flexing of the sheet did allow moisture in. Kind of makes you wonder if there is a design flaw in the use of such material! I have no need for such things nowadays myself f so a bit out of touch. Brian