Ive read all the posts about this subject but im not clear on one thing. Do you have to use double wall pipe when going though a wall thimble.i have All single wall stainless saf t pipe by heat fab from menards. Its all the same stuff in this kit for mr. heater heatstar. All category 3. So i would think i could do the whole run with single wall? HeatStar 4" Horizontal Stainless Steel Vent Kit.
http://www.globalindustrial.com/p/h...ntal-vent-kit-f102860?infoParam.campaiF102860 Category III Venting
http://www.globalindustrial.com/p/h...ntal-vent-kit-f102860?infoParam.campaiF102860 Category III Venting