Live in Western NY... need I say more? have a H E furnace and is vented thru foundation of house ( approx. 6-8" from ground) the exhaust PVC pipe is short and is straight out (no elbows)and the cone around the pipe is flush to the foundation. This winter, snow drifted and closed everything. had to clean it out. My question is can I build up the exhaust AND build like a little shelf to put over the cone to keep the snow away?