Is A Vapor Barrier Required For External Walls?

At time 5:37, you discussed and encouraged use of “vapor-retardant paint or a smart retarder” as best solution to retard vapor exiting to outside. I have two questions: Some brands of fiberglass insulation bats add craft paper to one side, aiding installation; is that paper acting as a vapor barrier? In another article, you interviewed two experienced architects with an unhappy client with in-wall water and mold; and the cause was discovered to be the client’s vinyl wallpaper, which in effect, acted as an interior vapor barrier, and that vinyl did not allow the wall to breath during warm weather. Please say more to distinguish the uses and differences between air barriers and vapor barriers. ~Steven, Utah

Still reading these comments? Suppose you live in zone 4 or above and you suffer from extremely low humidity inside the winter like in my case because i gave a woodstove and no humidifier? In that theres often higher humidity outside than inside in winter. Should you have a vapor barrier. Im guessing not.

So in a kitchen wall with metal studs and insulation, to the innermost of the unit, beside the neighbour, there doesn’t seem to be a vapour barrier. This wall does lead to the balcony, eventually. I’m installing cabinets and also some wood stud supports. So it’s not the wood which would now dictate a vapour barrier, I’m guessing. But I now understand why refinishing and repainting was recommended afterwards. I was wondering whether the wood dictated (because it was somehow special vis-a-vis moisture) the vapour barrier now that I’m adding some 2x4s, vertical and horizontal, in key points. Versus the configuration of the wall as a whole which decided it was not necessary. The reason I wondered about the wood as the instigator was because in the parallel other neighbour wall, near the outside of the building, there are metal and wood studs and there is a vapour barrier. The wall also leaked into small permanent closet walls, now gone, and was very drafty, which I noticed when the wall was open. The kitchen drywall is double, 1.5″, compared to the other bedroom wall which had adjoining closets. (Who on earth builds inbuilt closets that are tiny? Haven’t they heard of a standalone Ikea unit? That removal was a pain, which allowed me to lay my bed in a different orientation and gain 16sqft.)

had to take up all my NuCore Performance Rigid Core LVP – Cork backed. and removing old hardwood underneath. Some of the 20 yr old hard wood was warped in most areas and subfloor underneath being unleveled some areas. Making vinyl on top shift and make cracking noise seemed to be coming from between locking mechanisms. Floor Associate at the store where got LVP recommended put down sound dataning sentinl moisture barrier with this corked back LVP. My floor was Making a rice crispy sound some people say is do to the clicking locking system. To me flet like the vinyl floor was sitting to high on the cushion vaper barrier combined with vinyl floor already having cork back felt like it was apart of the problem. Also floor felt squishy with the exstra padding uncomfortable Synthetic feeling to me like it never formed or madded to the ground because of the exstra cushioning. Don’t know the difference with out the Cushion vapor barrier but my question is if I put down just a plastic non cushion vapor barrier because its going on a concrete subfloor would you recommend one and also a role on paint on vaper barrier to for exstra blockage you’d recommend? My concrete subfloor was reading 16/ 20% moisture levels directly after remove of old vaper barrier sure something to do with all moisture being traped in there for while. My installer said when i told him wanted to go with regular plastic non cushion vaper barrier said it will definitely make a worst annoying sound then the cushion vaper barrier.