Mold in the Mountains is about how this custom house Architect recognizes mold as one of the most important and undesirable results of improperly designed, incorrectly built, and wrongly operated houses in the mountains.
It is quite common, if not chronic, that nearly all mountain houses have mold. Your nose will tell you, then second you walk through the front door. And sometimes, you can smell it from the outside, at a distance of 40′ or more.
This architectural company (HOME ARCHITECTS ®) has been designing houses since 1967 (as the continuation of its founder’s practice and experience). And one of the most predictable maladies of just about any mountain house is that it will probably have mold, to one degree or another.
Which begs the question: why?
There are several reasons:
1. Because mold is everywhere. Literally. It is on you, inside you, on buildings, inside buildings. Everywhere.
2. Understanding item#1, it requires certain environmental conditions under which mold can grow and flourish.
3. Understanding item #2, what conditions are these?
4. Lots of humidity, if not outright natural, untainted water, such as rain water.
5. Lack of cleaning or ability to get to the places where the mold is growing.
6. Lack of air movement. Mold, which is organic (plant/ vegetation) likes all that humidity around it and wants that cloud of moisture to remain around it. Air movement dries the air, which mold doesn’t like.
7. Dirt, earth, soil. Mold doesn’t like spic and span surfaces.
Okay, understand items 1 through 7 above, what conditions would limit, restrain or prevent mold growth?
See below for the answers:
1.a. Accept that mold is everywhere, but hire a mold mitigation specialist to fumigate the spaces where you have mold and don’t want it anymore. Some people used to use bleach, wiped over the surface, but mold specialists will tell you that’s like weed whacking (the roots are still inside the materials below the top surface). Mold specialists that have experience (like a decade or more) that really know what they’re doing will explain that such a fumigation will not only kill the mold visible on the surface of the contaminated materials, it will also drive into the materials, killing the roots (remember: mold is a microscopic plant).
2.a-4a. Reduce the amount of humidity. A lot. This is typically accomplished by closing gaps in the building walls, roofs, foundations, then sealing the smaller joints, then applying waterproofing coatings to porous materials (like concrete and concrete block), then installing dehumidifier(s). What’s important to do at this point: have the dehumidifier(s) have at least a 3/4″ +/- diameter hard piping (such as PVC or other code approved hard piping) drain the condensate to outside the building, at a distance of 18″ or more and above the level of the ground at a distance that will make it difficult for pests to enter the pipe.
5.a. BEFORE doing the items 2.a-4a, thoroughly clean the surfaces to be mitigated of all dust, soil, debris, trash and other filth. Do not provide anything in which the mold can grow more readily.
6. a. Move the air. Forever. Even if inside special ventilation spaces, have fans move the air. Constantly. And because you have items 2a-4a making the air dry, you will be moving dry air, which mold doesn’t like.
7.a. Monitor the areas where the mold previously was and keep them clean. Do not allow accumulation of dust, debris, trash or other unclean material.
Alright then. We’re getting somewhere. What are some of the actual architectural details and construction methods used to help facilitate mold mitigation in mountain houses?
For instance: most retaining walls holding back the earth around most basements in mountain environments are made of either concrete block (also called “CMU”) or cast in place steel reinforced concrete. Unfortunately, these cementitious materials are porous. Which means they need to have a waterproof coating applied to their outside surface(and drainage fabrics and underground piping) during the original construction to keep free-flowing water from penetrating the retaining wall. Unfortunately, very few clients understand that there are different qualities of waterproofing materials.
The higher quality coatings are more expensive than lower quality coatings. Just like a higher priced lawn tractor will generally offer more features and durability than a cheap one. What typically happens when an Architect is not involved in the project: the client hammers the Contractor to make the house cost less money so the client doesn’t have to pay the Contractor as much to build the house. Given his/her marching orders to save money, the Builder then usually defaults to the cheapest materials possible (especially when there is no Architect involved). And so the Contractor typically uses cheaper quality waterproofing materials (like asphalt, which become brittle fairly swiftly and has a radical molecule in its chemistry (allowing mixing with H2O), allowing water to penetrate at these cracks) rather than a better coating (like polyurethane, which is more elastic and lasts longer). And so here we go: the lack of having an Architect involved results in cheaper materials that allow water to penetrate the retaining wall, which is heaven for mold: darkness, dirt, water. Yum.
See below for more:
So: if an Architect were involved, you’d probably get better subterranean waterproofing and that’s going to help a lot. The main point here: HIRE AN ARCHITECT. Otherwise, you’re at the mercy of people who are trying to cheapen your construction because they though that’s what you asked them to do.
Beyond that, for a basement retaining wall, what else can be done to prevent mold growth? Well: if you’ve got a house that is already leaking water through the retaining wall and exhibiting mold growth, because you happen to have purchased a used home that you had no control over, when it was built in 1981, what now? Well, this architectural firm sees this all the time. As a matter of fact, they just fixed a home like this in the mountainous region of western North Carolina. And the new homeowner didn’t want to have to pay the price to dig down all around the house’s foundation walls to clean, seal and re-waterproof the exterior side. So what now? Well, it so happens that this architectural company is knowledgeable of special chemicals that can be applied to the interior of foundation walls to stop the penetration of water. It actually works and has been tested on other projects.
And so, once that’s been applied (after fumigating) what then? Well, remember that item about keeping the air moving and dehumidified? So you then need to have the Architect (and this takes an Architect to understand exactly what to do) use special wall studs that permit air movement between them, then multiple dehumidifiers need to be installed, then have sections of ductwork installed between them and this special vent zone all along the basement retaining wall, then additional fans need to be installed to keep the air moving, then hard-piped condensate lines need to be installed to remove the moisture from the dehumidifiers. Whew. That’s a lot of technical know-how. This architectural company knows how to do this.
Now then, that’s the hard part. What are the easy things any homeowner can do to help prevent mold? Super easy: DON’T TURN OFF YOUR HEATING OR AIR-CONDITIONING WHEN YOU LEAVE YOUR HOUSE FOR EXTENDED PERIODS OF TIME. The most damaging thing any homeowner can do is thinking they are saving maybe 10 bucks a month on their electrical bill (or whatever), then turn their HVAC systems off or so low that their heat and air systems are pretty much useless in terms of mold prevention. DON’T DO THAT! It’s a false economy. How so? Because your mattresses will grow mold and be entirely ruined (resulting in you paying to have a trash company remove them from your house, and several hundred or several thousands of dollars to replace them). Same thing with your drywall, rugs, wood and nearly everything else in a house. Stop growing mold! That’s what you’re doing, every time you turn your thermostats either off or too low.
What can you do when leaving your house for weeks or months at a time? For heating: set the thermostats no lower than perhaps 65* or so. Any lower, and you’re going to probably warp or separate your flooring (including woods, laminates and others). And set your A/C no higher than perhaps 82* or so. Otherwise too much hot humid air, which mold spores love, will begin to build. When you are in residence, set your heat to around 69* and your A/C to around 75*. Under no circumstances should you ever shut your heat and air down entirely, nor shut off the main power to your house, unless you are having electrical work performed. Otherwise, all the money you have spent to make a nice house will be thrown away, because mold can and will grow. Some entire homes become so infected with mold, they become a total loss, a tear-down. What a waste, just to save a few bucks each month on the utility bill.
But there’s more to mold-proofing a house. We’ve only touched on a few things. More later. And hire an Architect to design your mountain project so that you won’t have to worry about this.
tags: mold in the mountains, Cashiers, Sevierville, Aspen, Highlands, Hendersonville, Lake Toxaway, Sapphire, Glenville, Portland, Orlando, timber frame, post and beam