Philadelphia Fiberglass Services commented on a video on YouTube.
The effects of moisture vapor migration through walls and ceilings and condensation at the dew points on the exterior skin of buildings are showing themselves in today's construction. This would occur with or without vapor barriers but moisture would dry far better if the walls were not insulated, like it was in the 1800's. As for the exterior, modern claddings are plagued with bad methodology and poor installation practices. Some of these materials should be outlawed and would be if it were not for the petrochemical mega corporation lobbyists. As for interior vapor barriers, I am in favor of an interior vapor barrier in the northern climates where the heating season is extended. For the exterior, it should be open or minimally covered in underlayment and without inhibiting barriers and housewraps, with true watershed and primary weather cladding. Never should an underlayment be accepting precipitation runoff. The “permeable” housewraps are not so permeable once the temperatures drop. They become vapor retarders producing dew points beneath the cladding. Venting is beneficial but is not the answer for interior moisture. Some seem to think that exterior moisture allowed into the basement or crawlspace in the winter causes the interior moisture to rise. This is not the case. There is less moisture held in cooler air than in warm air. Interior moisture needs to be addressed at the source. Mold is serious and to discount it is to do the public a disservice. I agree that there are “experts” running around swindling the public. I agree 100% that a company rendering the remedy should have a firm grasp on building methods. The problem is that the opinions are diverse and the education obtained by these “experts” is skewed by corporate interests.
Shared publicly•View activity
- Wow very well thought out post. Thank you. I don’t completely agree with interior vapor barrier in cold climate zones. We (Ohio) have full developments that are rotting. They put poly 6 mil on the backside of the drywall and called it an air barrier. I have some other videos on this stuff. This happens in the summer months with the AC being on and then vapor diffusion occurs on hot - humid days. Plus, let’s not forget about solar vapor diffusion. Most of our Ohio homes (brick) do not have weep holes or upper vent holes, do not have rain screens (Cultured Stone), not back primed (Hardy Board), or have dopuble Tyvek (EIFS) and a few more.. I think interior vapor barriers with perm ratings less than one may work in very cold climate zones like where SANTA makes toys. My bible is Building Science Corporation, Joseph Lstiburek, Ph.D., P.Eng., ASHRA, Cold Weather Climate Zones $30. Best book on earth.Jan 3, 2014
- There is a lot of disinformation in the industry and we do not want to mix up the vapor retarders with the weather barriers in the discussion. There is also much disinfo regarding mold and I feel that you are discounting the potential severity of the problem and leaving yourself open for liability while harming many who may look to you for answers.
It is the moisture even by your own admission that migrates to the dew points that condenses and feeds mold. This is speaking to moisture vapor. In the Northern climate and especially in Ohio which does not benefit from the Gulf Stream, interior moisture migrates through interior walls in the winter. It does not take a high moisture content in the interior conditioned space to produce condensation. The internal pressures of the summer months do not rival in reverse, those of the winter from within. Yes, there is more moisture content in the external air in the summer but the air conditioned space is not as cool as the exterior is in the winter months. Perhaps in the development to which you are referring, there are breeches in the internal vapor barrier that cause concentrated air bypasses that will cause accumulation of condensed moisture where mold and rot can compete to eat the structure. It would be the breeches like at window openings, seams, etc. that would leak. This goes for the upper ceiling areas also as bypasses cause major problems even and especially in thoroughly insulated attics.
As for external leak barriers as underlayments, I am against them altogether. No precipitation should ever reach the underlayment. Underlayments like Ice & Water Underlay, Window Tapes, Felts, etc. are not flashing details but the industry seems to refer to them as such especially in the side wall cladding. Bricks and stones need to be sealed. I know this drives people crazy that have been brainwashed. A reading on the moisture content needs to be taken and in dry weather, a proper sealing will ensure that the surface planes do not leak. Moisture should not be let into the structure unless a formidable screen wall with a one inch air space with a significant waterproofing membrane is installed. Keep in mind that when this type of system is used, if at least an R15 is not installed over it (which is rarely the case), condensation is a real threat from inside. There is another argument for interior vapor barrier. Perm ratings are bogus when you enter in the temperature difference on opposing sides of the medium. Air will not pass through when one side is warm and the other is cold. If you believe that try placing a boiling pot of water on a window sill (on the inside in the winter) in front of an ope screen. The moisture hardly passes through the screen before condensing. We know that the screen is much more permeable that any vapor retarder and we also know that the screen is cold initially, but it is an analogy that shows even an idiot that permeable vapor retarders do not work between opposing temperatures.Jan 6, 2014
- You are correct. You know your building science. Unfotunalty, they don’t build homes like this. Builders, engineers and architects mix up rules, climate zones, products and etc. Furthermore, the moisture building holding capacity is becoming lower and lower (hygric buffering capacity). Then you have the media brainwashing home owners with Energy Star, tighter homes, phrases that use the word sustainable and etc. I just spent 6 hours in a home where the homeowner moved out and is living in hotel because she believes that the fiberglass, non-visible mold, some common mouse droppings, unbalanced HVAC, HVAC ductless returns, is making her, husband, and her six kids sick. The home is a 3 bedroom, has 6 mil poly behind the drywall (1988 design before DR. Joe L. changed a section in his book (Moisture Control Handbook 1992-1994), has a running humidifier, has ice dams, has upper floor thermal bypass with some mold on attic sheathing (Cladosporium), bleach under every sink, crumbs, huge fish tank, dead fly’s, sewer back up (tree in front), foundation cracks and leaks (10 inch block, not reinforced with 9 feet of uncontrolled fill), carpets, long dryer vent . This almost sounds like the typical American Home. Thank god no pets in this house, If it’s not mold, then its radon, asbestos, EMF’s,VOC’s, lead, mercury, formaldehyde, air born particulate, bacteria, virus, chemicals, GMO;s, pesticides, ChemTrail fall out, fluoride, chlorine, air fresheners, and a few more. I will not make freak videos. I my mold book (15 years old now) I was freaking people out. I may be partially responsible for this mold craze because my book was sold to all the home inspectors 10-13 years ago, before Ballard mold case, Ed McMahon dead dog from mold, Erin Brockovich mold days. I was knew and spoke to Dr. Dearborn CWU Rainbows Babies about toxic mold that was killing babies in Cleveland (you know this where it all started right). Now 15 years later, I am not worried about people listening to me. People listen to their doctors and take drugs that kill them. People need to do their own research and make their own decisions. I have now become a “Stupid Simple” And yes 1-5% of the population does not fit into my realty. I am quite sure this group has a little more going on than some black toxic mold. PS what do you do?Jan 6, 2014
- All I can say is that is a mess of a house. There are those homes where you almost want to say "Call in a dozer" and start over. You can best see what we do by visiting the website:
Company started several decades ago with primarily roofing but branched out in several directions. We do a lot of what I call "moisture mitigation," but that always involves fixing the source which is either in the cladding, foundation, grading, or interior sources.Jan 6, 2014
- Saw your website. You re the smartest roofer I know. Good luck in your business. Thank you for posting. It is rear to get good posts that people can read and learn something. PS my client will never move back into that home. She actually wants it bulldozed just like you said. Take care and enjoy the cooler weather we are having.Jan 6, 2014
- Man,please don't call me a roofer. The trade has a stigma, but yes I am an old roofer.Jan 6, 2014
- sorry.Feb 2, 2014