What size Flexwatt???

Ok. I've been holding it off for some time but I'm looking into getting a rack system. Since I started out with glass tanks then gradually switched over to tubs. I was always under the impression that the Under Tank Heater is not to take up nomore than half of the enclosures floor space roughly 1/4, so if I had a 36" long enclosure I would use something around 11x11". My question is why is it that I only come across racks with 3" and 4" belly heat. Are there any rack systems which offer a wider heating area like using a 11" piece of flexwatt, by the way I'm looking into a rack that holds the sterilite 41qt tubs. I'd like to have a wider area of coverage for my female balls and sub adult male boas.

3" or 4" tape is all thats needed really.

Actually I think the Freedom breeder racks with 3" or 11".

It all depends on the environment you plan to keep them in. I think VPI doesn't use any heat and just keep the room in the 80's. They seem to have good luck with this. Initially since we kept our snakes in general living areas of our house before we set aside a room as the reptile room we liked the 11" in our home made racks as it did good for bringing the ambient temps of the air in the CB-70 tub up while room temps were maintained around 70 degrees. Now that we have a snake room that we keep between 78 and 80 degrees we were able to switch to 4" and now using vision racks with heat rope.

So IMO you need to look at the enviroment the rack is going to be in when setting everything up and choosing the heat tape you will use.