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Is a pain in the ass. We moved back to our larger campus facility this week and had to cut the tatami to fit around some posts.
Shit you'll need:
- Mat Knife
- Sharpened painter's tool
- Flat pry bar
- Tape measure
- T-square or Speed square
- Adhesive
- Mat Tape
- Marker
(obligatory wall of text warning...still half the length of your typical Wolfman post)
If you've done any sort of carpentry or honeydo work it's a fairly straightforward process. While I'd built a few subfloors, I'd never cut into any tatami and wasn't sure what to expect.
Tatami, at least the Zebra and whatever-brand tatami we had on hand - is basically just a vinyl surface wrapped around a chunk of composite foam (like a big fuckin carpet pad) with another rubber layer attached on the bottom. I'd (wrongly) assumed the foam would be one contiguous sheet, but it's actually a compressed aggregate of smaller foam chunks, again like a carpet pad. This is why you need the t-square: you could try your hand at a straight cut with the mat knife, but you may hit a dense section and jog the cut. This isn't the end of the world, but I was trying to keep the edges as flush as possible.
Could you just use a handsaw or sawzall to notch out what you need? Yeah, but the cut will be rough as shit, and you run the risk of losing foam and having the mat surface peel away. We elected to wrap the tatami surface back down the edges of the cut sections. Not only did this look great, but functionally it should keep the foam in and ameliorate the peeling problem.
Notching is a fairly straightforward process:
- mark the section you need to cut
- flip the mat over and draw your cutout. For a clean look, you can be dead-on with your measurements, or even 1/8 under as the foam will expand and push into the wall/post you're cutting for.
- cut through the bottom rubber with a mat knife and peel the layer off.
Now you're left staring at a chunk of composite foam which is glued to the tatami surface. Granted, you could just cut all the way through, but we wanted to fold the top layer of tatami over the cut so there weren't any rough edges.
The bitch was liberating the foam from the underside of the tatami surface. This was easiest to do on the cutout notch - the tatami surface wraps down the side and underneath the mat for about an inch. We sliced the sides and pulled the surface away from the foam. They don't use nearly as much adhesive on the sides or bottom so this was relatively easy, and gave me a good starting point.
We cut the foam into sections with a mat knife, careful not to cut *through* the top surface we were trying to preserve. At the same time, I came in from underneath with a sharpened painter's tool. The technique wasn't unlike trying to flip a stuck burger or pancake, but with a light touch to prevent poking through the surface from the underside.
Once we got the section free of foam, we cut the surface from the corners toward the center at a 45 degree angle, then cut out the middle of the section, leaving 3" flaps for all exposed edges. Those flaps were wrapped back down the edge and underneath of the mat. We had plenty of leftover adhesive that we'd been using to attach foam blocks to plywood for our subfloor, so we used that to glue the mat back to the foam, then mat tape to hold it all in place. We ended up with a cutout flush to the wall. It didn't matter *that* much since the wall will also be matted, but it still looked real pretty.
You'll wanna be diligent with your edges if you're trying to wrap the mat surface - you wanna keep them fairly square, but you've also gotta make sure not to slice through with your mat knife.
Cutting out for the posts was a bit more challenging, as they fell in the middle of the mats we were laying down. This was aided tremendously by having the mats build up to the poles squared up and framed in. If you're notching out for poles, you're not going to be able to re-adjust the mats in that vicinity for gaps once they're in place as the poles are in the way.
The cutting process was basically the same as the cutout for the wall, with a few important exceptions. Thank god the poles were square beams, because round would have been a goddamn nightmare.
We couldn't decide whether the cut in the side of the mat closest to the cutout should consist of two flaps of equal length, or one large flap (think double door vs field gate). In the end we went with the one large flap as it was easier to manipulate.
This presented a problem: although the cutout followed the same wrap-and-glue procedure as the notch, we didn't have extra material for the cut we made from the side of the mat to the cutout. We decided to use mat tape on both sides, running a strip from the tatami surface, down the side, and underneath. We then bridged the gap with another piece of mat tape. While you could simply leave the mat as-is and not have too much of a gap, I worried that over time the foot traffic and mat cleaning would cause the surface to peel away from the foam. Granted, if you're notching around a pole in the middle of your training floor that pole should probably be padded for safety and thus cover a decent portion of your cut, and we're assuming there won't be a ton of foot traffic in the area as there's a fuckin pole in the way anyway.
The other problem was that we were trying to get the foam out of a square section cut in the middle of the mat without fucking up the surrounding foam or damaging the surface . This was much more difficult than with a cutout from the side because we needed to somehow dig the foam out of the middle of the section, rather than scrape from the side. I ended up using a sharpened pry bar, which seemed to work pretty well. Once we got down to the underside of the mat surface we dug out enough foam to get the painter's tool back down, and away we went.
The end result was a really clean look that fit snugly around the obstacles while maintaining the integrity of the individual mat and the mat area as a whole.
I didn't take pictures of the process yesterday as I was the one doing the cutting, but I'll update this post with some pictures next time I'm back.
if you have any questions about building a sprung subfloor or cutting tatami, holler atcho boy.
Shit you'll need:
- Mat Knife
- Sharpened painter's tool
- Flat pry bar
- Tape measure
- T-square or Speed square
- Adhesive
- Mat Tape
- Marker
(obligatory wall of text warning...still half the length of your typical Wolfman post)
If you've done any sort of carpentry or honeydo work it's a fairly straightforward process. While I'd built a few subfloors, I'd never cut into any tatami and wasn't sure what to expect.
Tatami, at least the Zebra and whatever-brand tatami we had on hand - is basically just a vinyl surface wrapped around a chunk of composite foam (like a big fuckin carpet pad) with another rubber layer attached on the bottom. I'd (wrongly) assumed the foam would be one contiguous sheet, but it's actually a compressed aggregate of smaller foam chunks, again like a carpet pad. This is why you need the t-square: you could try your hand at a straight cut with the mat knife, but you may hit a dense section and jog the cut. This isn't the end of the world, but I was trying to keep the edges as flush as possible.
Could you just use a handsaw or sawzall to notch out what you need? Yeah, but the cut will be rough as shit, and you run the risk of losing foam and having the mat surface peel away. We elected to wrap the tatami surface back down the edges of the cut sections. Not only did this look great, but functionally it should keep the foam in and ameliorate the peeling problem.
Notching is a fairly straightforward process:
- mark the section you need to cut
- flip the mat over and draw your cutout. For a clean look, you can be dead-on with your measurements, or even 1/8 under as the foam will expand and push into the wall/post you're cutting for.
- cut through the bottom rubber with a mat knife and peel the layer off.
Now you're left staring at a chunk of composite foam which is glued to the tatami surface. Granted, you could just cut all the way through, but we wanted to fold the top layer of tatami over the cut so there weren't any rough edges.
The bitch was liberating the foam from the underside of the tatami surface. This was easiest to do on the cutout notch - the tatami surface wraps down the side and underneath the mat for about an inch. We sliced the sides and pulled the surface away from the foam. They don't use nearly as much adhesive on the sides or bottom so this was relatively easy, and gave me a good starting point.
We cut the foam into sections with a mat knife, careful not to cut *through* the top surface we were trying to preserve. At the same time, I came in from underneath with a sharpened painter's tool. The technique wasn't unlike trying to flip a stuck burger or pancake, but with a light touch to prevent poking through the surface from the underside.
Once we got the section free of foam, we cut the surface from the corners toward the center at a 45 degree angle, then cut out the middle of the section, leaving 3" flaps for all exposed edges. Those flaps were wrapped back down the edge and underneath of the mat. We had plenty of leftover adhesive that we'd been using to attach foam blocks to plywood for our subfloor, so we used that to glue the mat back to the foam, then mat tape to hold it all in place. We ended up with a cutout flush to the wall. It didn't matter *that* much since the wall will also be matted, but it still looked real pretty.
You'll wanna be diligent with your edges if you're trying to wrap the mat surface - you wanna keep them fairly square, but you've also gotta make sure not to slice through with your mat knife.
Cutting out for the posts was a bit more challenging, as they fell in the middle of the mats we were laying down. This was aided tremendously by having the mats build up to the poles squared up and framed in. If you're notching out for poles, you're not going to be able to re-adjust the mats in that vicinity for gaps once they're in place as the poles are in the way.
The cutting process was basically the same as the cutout for the wall, with a few important exceptions. Thank god the poles were square beams, because round would have been a goddamn nightmare.
We couldn't decide whether the cut in the side of the mat closest to the cutout should consist of two flaps of equal length, or one large flap (think double door vs field gate). In the end we went with the one large flap as it was easier to manipulate.
This presented a problem: although the cutout followed the same wrap-and-glue procedure as the notch, we didn't have extra material for the cut we made from the side of the mat to the cutout. We decided to use mat tape on both sides, running a strip from the tatami surface, down the side, and underneath. We then bridged the gap with another piece of mat tape. While you could simply leave the mat as-is and not have too much of a gap, I worried that over time the foot traffic and mat cleaning would cause the surface to peel away from the foam. Granted, if you're notching around a pole in the middle of your training floor that pole should probably be padded for safety and thus cover a decent portion of your cut, and we're assuming there won't be a ton of foot traffic in the area as there's a fuckin pole in the way anyway.
The other problem was that we were trying to get the foam out of a square section cut in the middle of the mat without fucking up the surrounding foam or damaging the surface . This was much more difficult than with a cutout from the side because we needed to somehow dig the foam out of the middle of the section, rather than scrape from the side. I ended up using a sharpened pry bar, which seemed to work pretty well. Once we got down to the underside of the mat surface we dug out enough foam to get the painter's tool back down, and away we went.
The end result was a really clean look that fit snugly around the obstacles while maintaining the integrity of the individual mat and the mat area as a whole.
I didn't take pictures of the process yesterday as I was the one doing the cutting, but I'll update this post with some pictures next time I'm back.
if you have any questions about building a sprung subfloor or cutting tatami, holler atcho boy.
