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1.1 oz Silpoly PU4000

$8.25 /yd

1.1 oz Silpoly PU4000

$8.25 /yd

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    This is the high water-resistance version of our 2nd generation 1.1 oz Silpoly line of coated materials. This fabric is coated with a silicone/PU layer on one side, then a multi-pass PU coating on the other to create a highly waterproof/non-breathable fabric.

    Same silpoly benefits of lower water absorption and increased UV resistance, but with a much higher waterproof rating. The PU4000 also has less bias stretch, making it easier to sew.

    Great for projects such as tents, ground sheets, tarps, ponchos, gear sacks, pack covers, or any application where lightweight, highly waterproof/windproof fabric is needed.

    *Note - shiny side is PU4000 and dull is sil/PU. If seam sealing this fabric, you will need a sealant intended for PU coated materials (e.g. Seam Grip).

    Want to quickly compare all our lightweight coated/non-breathable fabrics? Check out the "Fabric Comparison Guides" on our FAQ page.

  • Product Details
    Width ~58''  (147.3 cm) usable, selvedge trimmed
    Weight  1.1 oz/yd 2   (39.7 grams) (*~1.4 oz/yd 2 with sil/PU + PU4000 coating) 
    Denier 20D x 20D 
    Finish/Coating Sil/PU mix one side, multi-pass PU4000 other side
    Hydrostatic Head (i.e. waterproof rating)

    ~4000 mm 

    Data Sheet

    Download here


Customer Reviews

Based on 71 reviews
Drew Boswell
perfect poncho material

This turned out to be the perfect material for a custom poncho sized to fit over my backpack, obviating the need for a pack cover. Finished weight is 7.8 ounces, which is less than a Frog Toggs poncho weighs, yet it offers more coverage. The new poncho got a tough workout the first two weeks in March on a 10-day, 120 mile section hike of the AT in North Carolina and Georgia where it kept me and my gear dry during two days of torrential rains and high winds. This fabric is an excellent choice for anything you want to keep dry.

Thanks for your review Drew! Making sure your gear stays dry is essential, especially in the green tunnel! We're glad you got to test out your MYOG poncho and that it worked wonders, Happy Hiking!

Mike Turner
Excellent quality

Bought this to use as reinforcement on my tarps as its bit stronger than the normal 1.1oz Eco silpoly which is the main fabric that I use. Works beautifully. Also speed of packaging and delivery is superb. I live in the UK and it could not be simpler.

Thank you for the review! We're glad to hear that the quality of our product is excellent and that it worked well as reinforcement on your tarps. We're also glad to hear that the speed of shipping and packaging is superb. Happy Making!

Philmont Tarp Material

I purchased this to make a Philmont compliant tarp that would weigh substantially less than the crew gear one provided. Tarp was 10x12 with grosgrain loops to as tie outs. I laminated an additional reinforcement layer at each tie out (PU side to PU side) using Seam Grip +WP that I thinned with toluene and applied with a brush. No delamination after 12 days at Philmont with rain for a few hours to all day on 10 of those days. This material is essentially rainproof and will actually hold standing water. Things remained dry after 12+ hours of driving rain at over 8000 ft of elevation. I have not weighed the tarp alone, but with stakes and line it was just under 2 lbs.
Fabric was super easy to work with compared to membrane silnylon and is much stronger at resisting thread pulling through the fabric when under tension.

Thank you Dave for the fantastic write up and review of the 1.1 oz Silpoly PU4000 for your tarp! We would love to see photos from your Philmont trip, be sure to tag us on social media!

Teddy Warfle
Silpoly PU4000

Used for a bathtub floor for a tent. The PU coating reduces the slip of normal silpoly making it a lot easier to sew.

Perfect application! We're glad you found this fabric for your bathtub floor, enjoy!

David J
Great for tent tubs

I have made a few free standing tents over the last 2 years and I found out silnylon is a slip and slide when used as a tent floor. This Silpoly PU4000 has enough urethane to create some traction and still stay pretty light. I just wish RSBTR would update their projects page so the DIY community can continue to share and inspire

Thank for your review David! That is a great idea for a project. We are working on a new space for makers to share projects, stay tuned! We'd love to see photos of your project, here is a link if you'd like to share! https://forms.gle/erH82vVyNZF8UPao8