PDA

View Full Version : Piecing an 8'x8' ground cloth...



tlbj6142
02-22-2005, 14:56
I need to make an 96"x96" silnylon ground cloth. I don't care where seam(s) are located and silnylon is ~60" wide. How can I best minimize fabric waste?

60"x96" plus 36"x96"?

The Cheat
02-22-2005, 15:30
I need to make an 96"x96" silnylon ground cloth. I don't care where seam(s) are located and silnylon is ~60" wide. How can I best minimize fabric waste?

60"x96" plus 36"x96"?
You will need to figure out the exact measurements to use (I just guessed on the numbers below :o and inserted them for clarity's sake), but there should be a way to do it with no waste:

Picture a rectangle, longer than it is tall. 60" tall by 150(ish)" long.
Scribe a line from the top middle to each bottom corner. This will make two triangles approximately 60" by 96" by 75" as well as one larger central triangle.
Cut these two smaller triangles off.
Butt the two right angles against each other on the 60" side and sew them together.
You should now have two triangles the same size. The long side being the length of the former rectangle (150").
Now sew the two large triangles together on the 150" side to make one large square.

tlbj6142
02-22-2005, 15:50
Excellent. A few pencil drawings later I figured it out.

2 seams, zero waste. One which crosses the diagnal of the 96x96 square and the other perpendicular to the first seam running into one of the corners of the 96"x96" square. Forming a Tee in the middle of the square. Consuming ~4.2 yrds of (60") material.

chris
02-22-2005, 16:28
If you are not already attached to silnylon, think about using a 2 mil painters drop cloth. They come in various sizes, but I think mine was 10 by 12 feet. If I recall correctly, the roll was something like $4, and you don't have to sew anything. Durability is fairly good. I've got a few minor punctures in the one I've been using since mid summer, but as cost isn't a big deal, durability isn't much of one either.

tlbj6142
02-22-2005, 19:57
I have a piece of some type of plastic (former drop cloth) here at home. Not sure about the milage, but it has to be at least 2mil, probably 4. Its my back up plan if I get lazy.

Though I have considered sewing the floor to the netting (I'm making a 3-person tarptent-like structure), in which case drop cloth is probalby out of the question.

chris
02-22-2005, 20:01
If you copy Henry's design (i.e, no sewn in floor, but with draped netting), you'll get a good bug structure. One advantage of having a separate groundcloth and not a sewn in floor is for use in shelters. A downside is that you don't have quite the weather protection, and you have to work a bit to bath tub it.

hikerjohnd
02-22-2005, 20:08
You will need to figure out the exact measurements to use (I just guessed on the numbers below :o and inserted them for clarity's sake), but there should be a way to do it with no waste:

Picture a rectangle, longer than it is tall. 60" tall by 150(ish)" long.
Scribe a line from the top middle to each bottom corner. This will make two triangles approximately 60" by 96" by 75" as well as one larger central triangle.
Cut these two smaller triangles off.
Butt the two right angles against each other on the 60" side and sew them together.
You should now have two triangles the same size. The long side being the length of the former rectangle (150").
Now sew the two large triangles together on the 150" side to make one large square.
You are a god among men! I never would have figured that out! :sun

tlbj6142
02-22-2005, 21:41
If you copy Henry's design (i.e, no sewn in floor, but with draped netting), you'll get a good bug structure. One advantage of having a separate groundcloth and not a sewn in floor is for use in shelters. A downside is that you don't have quite the weather protection, and you have to work a bit to bath tub it.This structure is being built to be primarily used when hiking with my children. I decided to go with attached bug netting because its lighter than the "insert" approach.

I see the attached vs. detached floor debate like this...

Pros: Better wet weather protection (if tub'd), crawling bug protection (more of a Mom issue than a "real" issue), easier setup. Better solution when staying at designated sites (fewer "good" sites resulting possible drainage issues, etc.)

Cons: More sewing. Less flexible shelter setup options. Can't easily "opened up" if bugs are not an issue. Lighter?

chris
02-23-2005, 10:53
My suspicion is that the floorless model plus a groundcloth would weigh about as much, if not more, than a floored model. The main thing is flexibility. I like to cowboy camp (i.e, sleep out) whenever I can, and having a separate ground cloth helps alot. Additionally, I end up setting up in some obscure places with rocky/jagged ground. So, I tend to be hard on ground cloths, which are easier to replace than patching a floor. For family stuff, though, this probably doesn't matter, though.

The Cheat
02-24-2005, 14:45
You are a god among men! :sunNow, THAT is funny! :clap

plodder
02-24-2005, 18:08
Wicked slick math skills. Where is my geometry book?