Tyvek vs XFOIL, the Polycro Alternative: Tent Footprints Compared

Oct 2

5 min read

First things first: XFOIL is not better than Tyvek. Each material suits a different kind of use. Tyvek forgives rough handling. XFOIL is lighter, packs smaller and is waterproof. Online, the two are almost always compared by anecdote – “it held up fine for me”. Here we put the datasheets side by side and say what can be read from them and what can’t.

Tyvek groundsheet: tough, but not waterproof

Tyvek is water-repellent, not waterproof. Under pressure – when you kneel or lie on wet ground – water can come through, and the datasheets for the soft grades 1442R and 1443R list no hydrostatic head. What Tyvek gives you in return is forgiveness: sharp stones, thorns, sitting and packing on the sheet. XFOIL is a closed film and waterproof as long as it has no hole, but it asks you to check the pitch first. The sections below show the datasheet values behind both statements.

Who is writing this

We sell XFOIL, not Tyvek. So three rules apply to this article, and you can check each of them.

Every figure comes from a datasheet and is quoted with its test standard. Where we convert, the calculation is shown.
The Tyvek figures come from DuPont, and the sources are linked.
Where Tyvek performs better, we say so without a qualifying afterthought.

Which Tyvek are we talking about?

Tyvek is a product family with many grades and thicknesses. Hikers mostly buy the soft grades 1442R and 1443R at 43 gsm. There are also stiffer, paper-like grades such as 1056D at 55 gsm and 175 µm, and construction sites use Tyvek HomeWrap, which has different values again. Anyone comparing Tyvek should say which one. The table shows the soft grades.

The tested values

Property	Tyvek 1443R	Tyvek 1442R	XFOIL
Basis weight	43 gsm, ASTM D3776	43 gsm, DIN EN ISO 536	18 gsm
Thickness	155 µm, ASTM D1777	145 µm, DIN EN ISO 534	19 µm
Tensile strength MD / CD	49 / 48 N per 2.54 cm, ASTM D5035	44 / 38 N per 2.54 cm, DIN EN ISO 1924-2	135 / 125 N/mm², ASTM D882
Elongation MD / CD	11% / 20%	not stated	130% / 120%
Tear strength	9.8 N, ASTM D2261	11.2 / 11.0 N	17.5 / 16.5 g, ASTM D1922
Structure	Spunbonded HDPE fibres	Spunbonded HDPE fibres	Cross-linked polyolefin film, unperforated

The columns use different test standards. The tear values are not directly comparable: Tyvek is tested by the tongue tear method, XFOIL by Elmendorf.

Tensile strength: no winner

The values come in different units because nonwoven and film are tested to different standards. Converted to the same 2.54 cm strip, it looks like this:

XFOIL: 135 N/mm² × 0.019 mm = 2.57 N per mm of width, or about 65 N.
Tyvek 1443R (43 gsm): 49 N, ASTM D5035.
Tyvek 1442R (43 gsm): 44 N, DIN EN ISO 1924-2.
Tyvek 1056D (55 gsm): 120 N, DIN EN ISO 1924-2.

Against the soft grades, XFOIL is ahead in these datasheets; the stiffer grade 1056D is well above it. Test methods and test speeds differ as well. So tensile strength doesn’t settle the choice – waterproofness, weight and behaviour when damaged do.

Waterproofness: XFOIL is waterproof, Tyvek is not

XFOIL is a closed film without pores, so it is waterproof as long as it has no hole.

Tyvek is a nonwoven made of fibres. It is water-repellent but not waterproof: under pressure – when you kneel or lie on wet ground – water can come through. The datasheets for the soft grades 1442R and 1443R list no hydrostatic head.

Then there is ageing. Tyvek gets softer with folding and crumpling because the bond between the fibres loosens. The datasheet lists a delamination strength of only 0.25 to 0.58 N. With every trip the sheet lets more water through, and eventually dirty water from the ground as well. We don’t know of a measurement series on this; it is practical experience.

Some condensation can collect under XFOIL in the morning. You wipe it off when you pack up. Under Tyvek there tends to be less condensation, because the nonwoven lets vapour through.

Weight and packed size

Calculated for 1.5 m², a typical cut for a one-person tent:

At 1.5 m²	XFOIL	Tyvek 1443R
Weight	about 27 g	about 65 g
Material volume	about 29 cm³	about 233 cm³

Volume is area times thickness. Folded, both gain some air, but the ratio stays the same. Folded XFOIL fits in a side pocket; Tyvek stays a flat parcel.

Rough handling: Tyvek is ahead here

Tyvek is a web of fibres that slows a tear down. XFOIL has no such web: once there is a hole, a tear can run on under tension. If you don’t want to search your sleeping spot thoroughly for thorns, sharp stones and sticks before pitching, and you also sit or pack on the sheet, Tyvek is the better choice.

With XFOIL you look over the pitch first and clear away thorns and sharp sticks. A small hole is patched with a piece of tape.

Cleaning

XFOIL has a smooth, closed surface. Rinse, wipe, let it dry briefly and it is ready to pack again – even at a stream on the trail.

Tyvek holds dust, sand and clay in its fibre surface and dries more slowly.

Durability

According to user reports, Tyvek lasts many seasons even with rough use, but it gets softer and lets more water through over time. We don’t know of any measurement series on this.

With proper care, XFOIL lasts many hundreds of kilometres. There are reports of hikers who have walked the Pacific Crest Trail with it, carrying a little tape for repairs. It stays waterproof as long as you tape any holes.

Which material suits whom

Whether you call it a groundsheet, a footprint or a ground cloth, the question is the same: how much weight and pack size do you want to save, and how much care are you willing to take in return?

Tyvek suits you if you are rough on your gear, don’t want to search your sleeping spot thoroughly, also use the sheet to sit and pack on, and weight and packed size matter less to you. You accept that Tyvek isn’t waterproof and lets more through over time.

XFOIL suits you if weight and packed size count, you want a waterproof layer between ground and tent, and you are willing to check the pitch briefly and tape a hole.

How XFOIL differs from window insulation film and packaging film is explained in our guide to ultralight films.

For sizes by tent model, see our groundsheet sizing guide. The test methods behind the strength values are explained in How strong is Polycro really? If you want to see the film itself, the XFOIL ultralight groundsheet is in our shop.