Tarp seam direction

**100milerunner** · 01-22-2013, 21:10

My winter project is a DIY tarp. I'm following the DIY Supply plan for a 11'Lx10' wide tarp which calls for the seam to run lenthwise. I intend to use a ridgeline with the tarp so I can move the tarp lengthwise along ridgeline to center it over the hammock.

I just got my fabric in the mail. I had expected 60" bolt but to my surprise my cut is 66" wide. My question is, is running the seam perpendicular to the long dimension not recommended? Running the seam this direction would be more efficient with the material I have.

**JohnSawyer** · 01-22-2013, 21:54

Speer's book that started it all had his 8x10 tarp with a seam permpendicular to the ridge... Holds just fine on mine...

John

**100milerunner** · 01-23-2013, 08:10

Yep, you're right. I checked out Speer's design. Thanks for the help.

**Detail Man** · 01-23-2013, 08:51

It will work. Just understand that when pitched, a perpendicular seam will have the force on the seam concentrated at the ridgeline. If the seam runs parallel with the ridgeline, the force is dispersed along its length.

My winter tarp utilizes the whole 66" wide fabric.

**100milerunner** · 01-23-2013, 12:37

Originally Posted by Detail Man

It will work. Just understand that when pitched, a perpendicular seam will have the force on the seam concentrated at the ridgeline. If the seam runs parallel with the ridgeline, the force is dispersed along its length.

My winter tarp utilizes the whole 66" wide fabric.

Right-o. My assumption is that with a continuous structural ridgeline supporting the tarp the stress on the seam will be reduced. I'll use prusik loops to fasten the tarp to the ridgeline.

This is my first "real" tarp and I'm going for an all-around use design but I want to try to keep the weight to 16oz. Based on the actual weight of this fabric I'm going to right on. For a winter specialized tarp 11' wide tarp with integral doors would be a nice.

Thanks for your help.