Bob's A-Frame Greenhouse — You can build a greenhouse like this, too!

Northern Greenhouse Sales Inc.

- fastening products -


Our Original Polyfastener is a two-part smooth hard poly channel and insert strip that tightly locks poly to the greenhouse frame.

If you need to be able to take your poly on and off at certain seasons of the year, Polyfastener may suit you better than Cinchstrap or lath. The roller tool and hook tool allow you to attach and remove and reattach the poly with relative ease. Polyfastener is designed to allow such easy removal.

We recommend Polyfastener if you are securing any large expanse of poly which will be attached only around the perimeter (such as a rebar greenhouse or other Quonset), because the Polyfastener is designed to absorb or cushion the stress of such large poly panels in windstorms. With no direct contact with nails or screws the poly will not tear at the contact point along the Polyfastener. Use our cheaper Cinchstrap on small greenhouses or if nailing down the poly on every rafter.

A new Partly Metal Fastener will be available shortly. For more information, phone Bob at 1-204-327-5540 or fax at 1-204-327-5527

Advantages Of Polyfastener

Easy Application

Simple and fast. Please be sure to look for and follow the illustrated instructions that will be enclosed with your order. It is important to stretch the Polyfastener as you are applying it to the building for the first time. Secure by wood screws or nails, staples, pop rivets, or double-sided self-adhesive foam tape for inside use with smaller gauges.

Polyfastener Installation Tight Seal

Stops drafts and costly heat losses, virtually eliminates water leakage.

Less Abrasion = Longer Poly Life

The smoothness and round corners reduce abrasion. When wind flexes poly attached with wooden lath, it rubs on the lath slowly causing abrasion leading to tears.

Ideal on Curved Rafters and Frames

It bends easily as it follows the contour.

Flexible Fastener = Longer Poly Life

Polyfastener absorbs and cushions the quick, strong lateral motion of poly flexing in high windstorms. Stretching minutely, it reduces tears and cracking. The stress is evenly distributed along the entire length of the channel, NOT concentrated at one point.

Saves On Time and Lath Cost

Operators of large greenhouses usually use Polyfastener ONLY around the perimeter rafters. Why? Because if the poly becomes loose you can just unzip and re-tighten and re-lock it with Polyfastener absolutely no damage.


The clean, white, smooth surface is pleasing, eliminating the need for painting lath.

Poly Can Be Applied In Haste (And Later Re-Tightened)

I mean "haste" in two ways. Polyfastener is fast to use. But also you can apply poly in haste, even sloppily, too loose, rushing to beat a snowstorm (which always seems to happen to us). However with Polyfastener, no problem. Wait until a warm day comes along, unzip the poly, tighten it, and re-lock again.

Inflated Structures

Being airtight, it's ideal to secure doubled poly layers in inflated greenhouses.

Portable Reusable Seam

What you can get is a reusable fastener. A sewn seam only lasts as long as the poly. Polyfastener can be used over and over even be moved around to other structures. If your fabric tears, take it down, salvage the good, and make the size you want by using poly-fastener to "sew" or join two pieces of poly together. There's no waiting for someone else to sew you a new piece. Be sure both pieces of poly come out the wide-lip side. This is vital!



By far the most popular is the 800 gauge, 1 1/8 inches wide, used for 6 to 12 mils poly and also for joining 2 pieces of woven poly together. The 900 gauge is made to fasten 2 or more sheets of 13 mils woven poly. We can also supply lighter and heavier gauges for securing 1 to 30 mils.

Insert Strip is available separately if required.

Plastic Tools

A Polyfastener Roller Tool is needed to snuggle the insert strip into the channel, which has to fit tightly and snugly. For cool weather jobs and/or large installation jobs, we would suggest the Heavy Duty Polyfastener Roller Tool instead. The Polyfastener Unzip Hook tool is used to unlock the strip.


Free sample of "Polyfastner holding a piece of poly" sent on request. If you want a sample of Polyfastener showing it "joining 2 pieces of poly together" ask specifically for that. Illustrated instruction sheet also available if requested. A shipping fee of two dollars does apply.

Before Ordering: Please see our Vital Measurements chart for important ordering and measurement information.

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