UKC

I want to make a footprint/groundsheet for my tent but am confused by the different types of materials. This one was recommended to me as lightweight, waterproof and tear resistant.

http://www.pennineoutdoor.co.uk/P2GR-PU-coated-Nylon-Ripstop

and some of these look good

(can't post ebay link...)

They're all PU coated ripstop nylon which sounds good, but they're all described as 'water resistant' (not water proof) and some places even mention occasionally re-proofing PU coated nylon. The reason I want one is because I'm fed up re-proofing tent groundsheets and want a properly waterproof, but lightweight sheet underneath it. Does water resistant mean water proof these days? I've not found any lightweight camping/outdoor material listed as water proof so far.

If I thought goretex was actually waterproof long term I'd invest in a sheet of that, but it's not. Short of buying a plastic sheet from the builders yard, what do I have to do to get properly waterproof footprint material? I've heard people mention the roofing material Tyvek, but again that's a breathable membrane material, so I put that in the same category as goretex. Pricey too. At the moment plastic is winning, but it will perish/crack/tear over time, and sewing tabs on the corners won't be particularly strong. Suggestions would be much appreciated!

In reply to NottsRich:

Make sure the side that the tent sits on is not slippery against the tent. A world of pain awaits if it is! I put the footprint upside-down on my new tent a couple of weeks ago and it was a nightmare!

In reply to NottsRich:

this stuff:
http://www.needlesports.com/2751/tent-underlay.aspx
is worth considering - makes a big difference to warmth. bulky though.

I'm considering getting a tyvek groundsheet from backpackinglight:
http://www.backpackinglight.co.uk/shelter-accessories/WB107.html

which does not seem too pricey.

In reply to NottsRich:

Possibly 'tanking membrane' that builders use to keep basement/cellars watertight. No personal experience, but I've heard it mentioned on Grand Designs!!

In reply to NottsRich:

Cuben fiber is properly waterproof and very light. Zpacks.com sell a cuben fiber groundsheet:
http://www.zpacks.com/accessories/bathtub_groundsheet.shtml

I have a tent from Zpacks that is made entirely of cuben fiber and no water has ever gotten in it.

In reply to NottsRich:

I just use the blue builders tarp, the one with nylon woven into it, from B&Q or wherever, works fine on my TN Laser

In reply to NottsRich:

Another vote for Tyvek. Very, very, light. It is not "totally 100% water tight" (very little is that won't tear/puncture easily) but has more than a high enough head that water will not press through if you were to kneel on it. Quite good abrasion resistance too. You might be able to get a couple of meters from a builders merchants far cheaper than an outdoor supplier will sell you a foot print.

In reply to NottsRich:

I use an old Polythene survival bag. It is totally waterproof.

Tyvek is available reasonably cheaply on Amazon, by the metre.

In reply to NottsRich:

you can buy tyvek by the metre here https://www.insulationsuperstore.co.uk/product/tyvek-supro-breather-membran... so it's fairly cheap.

then just sew 2 pieces together if required for tent width and cut to suit.

Davey

In reply to Dark-Cloud:

and it only costs £4

Thanks all, some good suggestions there.

I'll look into Tyvek as that link does seem cheap. I want 1.5m wide though, not 1m, to minimise sewing.

The blue tarps are quite sturdy, but a bit bulkier. The nylon pattern never seems that strong to me, but I guess for a tent footprint it'll be fine.

In reply to NottsRich:
I made a footprint for my single-skin bivvy tent using Double Glazing Film from Wickes which is a very light, very tough, clear plastic sheet. I made it doubled up, with the corners reinforced with duct tape and elastic loops added to attach to the corner pegs. It weighs about 80g and has not punctured or torn after maybe 40 nights use. Total cost about £5 as I've still got half of the film left over.

In reply to NottsRich:

I'd avoid anything that requires stitching as that's just building in a weak point. Could you use a simple vapour barrier such as this? (It's 2.5m wide so no jointing required)

http://www.screwfix.com/p/vapour-barrier-green-300ga-2-5-x-20m/12869?kpid=1...

In reply to NottsRich:

I use an old survival bag under my ME Dragonfly. Seems to work pretty good.