A simple explanation of what air sealing is, it is the work performed on the home to reduce the amount of air infiltration into the home by sealing small and sometimes large gaps and crevices.  I utilized the DO–IT–YOURSELF Guide to Sealing & Insulating with ENERGY STAR to perform the air sealing in the attic before installing insulation.  These holes in the home can waste approximately 25% of the typical homes heating and cooling cost and is almost always the most cost effective improvement that can be done to most homes to reduce the utility bills and increase the indoor air quality (IAQ).

Air sealing not only helps reduce your heating and cooling costs, but sometimes more importantly, air sealing helps to improve the indoor air quality and durability of the home.  Tighter homes typically have less dust because not as much gets pulled in through these cracks; they are typically more durable because excessive air and moisture does not enter the walls or attic that could cause mold and rot.

The goal of air sealing your attic is to make the ceiling as air tight as possible to stop any air movement.  Now most home owners don’t think of their attic being full of holes.  However it is full of them, plumbing stack penetrations, wires, can lights and other ceiling fixtures.  If you hold your hand over these holes, you can feel the hot or cold air from inside your home making its way into the attic, costing you money.  Because as this conditioned air leaves your home, unconditioned air is being pulled into your home through other gaps or crevices in your home, typically in the basement (more on sealing the basement in a future post).  When your home has low levels of insulation, it is easy to find these holes.  However if you have good levels of insulation, you can find these holes by looking for discolored insulation, as most insulation types are air filters and the discoloration is a sign of air movement.  So review the air sealing guide, buy a few tubes of caulk and cans of Great Stuff and seal up those holes and start saving.

Here is a video series on the Fine Homebuilding magazine website on air sealing your attic that is worth watching, or check out other attic air sealing videos on YouTube.

So let’s stick with the title and what I do not enjoy about my job.  First, 90+ degree days, it makes for very uncomfortable working conditions as the attic is 100+ degrees.  However that is a condition of the job and is only an issue of comfort.  The hardest, as well as worst part of the job is delivering news to customers as I was reminded of today.  First is the customer that already has decent levels of insulation and based upon calculated paybacks and program goals do not qualify for very attractive incentives for energy efficiency improvements through the utility rebate program that we do work for.  I get a lot of eye rolling, but that is easy to handle, just lots of additional table talk which can add a lot of time to an appointment that only allows 4 hours to inspect, test, generate a report and present it to the customer.  However the absolute hardest part about my job is telling a customer, especially an assisted customer that is getting free work done that cannot have any air sealing or insulation work done until combustion safety issues have been resolved such as back drafting water heaters, or high CO levels.  This can really tug on the heart strings when you are in a home that has little to no insulation and you can see they would greatly benefit from lower utility bills and truly cannot afford to make some of the repairs necessary, yet their income level is not low enough to qualify for weatherization assistance that would actually make these repairs.

Now let’s change pace and talk why I enjoy my job and a little about what I do.  A lot of it is the people.  Every day I am meeting new people and with over 500 appointments over the past year performing home energy audits and quality assurance inspections, I have met people from all walks of life.  Also those last couple of years working in an architecture firm, I was really focusing my educational pursuits on building science and how the structures go together as well as how they are going to perform.  So performing energy audits is putting me in the field of building science, I am seeing what works and what does not work.  Finding things in our existing homes that can not only help increase the energy efficiency but help increase the durability of our homes.  Because let’s face it, our homes started to rot once we began introducing insulation and mechanical cooling.  So there are precautions that need to be taken when building our homes and office buildings, especially when we tighten the structures and add more insulation.  So even though climbing through attics and crawling through crawl spaces is a necessary part of the job, it is an educational opportunity that is all scalable to larger commercial structures.  As my supervisor who has been in this industry since the early 90’s says, when I return to architecture I will be a much better designer.  I can only agree with him as I see shortcuts that are taken by builders to save a buck that cause the occupants to have increased energy bills for the lifetime of that building as well as homes or additions designed by local architects that have high levels of air infiltration that cannot be fixed without gutting the house.  I will be able to focus on those details that will make certain the structure will perform as designed.

So what do I do on a daily basis?  I inspect homes to find ways for home owners to increase the energy efficiency of their home and reduce their utility bill and in a lot of cases increase the durability of the home.  I test their combustion appliances insuring that they are performing to manufacturer specifications and not creating unsafe conditions in the home.  I also manage people as I deal with different personalities from the ones who could care less that you are in the house to those that follow your every move and ask questions along the way.   Also I am a salesman, as the primary purpose for the home energy audit is to get people to increase the energy efficiency of their home and to take advantage of the incentives from the utility company and hire one of our program contractors to perform the work.   Then there is the aspect of my job when I am going back to the homes to inspect the contractors work to ensure they are doing the work properly and installing the insulation to the recommended levels in addition to making sure that the house is still safe.

One question we were asked to prepare for as a panelist on alternative careers of architecture at the AIA Ohio Regional Convention that was never asked is “Do you have an interest in returning to architecture?”.  The short answer is yes, I have too much passion for the profession and love creating or altering structures and solving each problem that the clients bring that I could never fully leave it.  However I don’t think I can return to a traditional design firm, I want to have more control on how the buildings go together and the methods used to ensure that the client is getting a well designed and constructed building.

Therefore it is time to resurrect the building science posts and go to my favorite resource for up to date building science research at Building Science Corporation.  So enjoy some advanced research on ice dams.

BSI-046: Dam Ice Dam

By Joseph Lstiburek

Ice dams are big problems because they often lead to water leakage into building assemblies, and more seriously, to falling ice that can be fatal (not kidding here) and to the weight of ice leading to structural collapse of roof overhangs and the shearing of deck assemblies when large masses of ice fall on them.

The strategy to control ice dams is fundamentally straightforward: keep the roof deck below freezing when the outside temperature is below freezing. Pretty easy you say? Not necessarily, as we shall see.

Historically, we have tried pretty much everything except the right thing to control ice dams. In New England where I live, older buildings use metal “slip” surfaces to get the snow to slide off the roof, preventing the ice dam from occurring at the roof edge.

Continue reading the article at buildingscience.com

View some of our own ice dam photos on our facebook page.

]]> http://www.symhome.net/blog/2011/02/building-science-sunday-ice-dams/feed/ 0 http://www.symhome.net/blog/2010/08/basement-finishing/ http://www.symhome.net/blog/2010/08/basement-finishing/#comments Mon, 09 Aug 2010 12:30:32 +0000 Joshua Lloyd http://www.symhome.net/?p=1045 A recent article in my local newspaper titled “Building a better basement” explains the difference of using traditional stick framing and drywall with panel systems for basement remodeling projects.  So, naturally red flags went up for me when I saw the title.  Primarily because what we have done in the past that we thought were the right things to do, are really not and are causing lots of problems today.  Especially the four letter word “mold”.  I think back to when my father finished our home when I was younger putting up the sheet of plastic (vapor barrier) before applying the paneling to the insulated stick framing, not to mention the rotten wood I found when tearing down finished basement walls in my own home.  If you are wondering what I may be afraid of, check out a couple of studies on insulating existing basements I posted last year.  (Building Science Sunday: Basement Insulation)

I want to take a little time and explain some of these systems mentioned in the article a little further and make a couple of suggestions.  Now the good thing is that all the companies mentioned in the article all agree that the basement has to address any moisture issues if any first.  Because if you have water problems in your basement, it doesn’t matter how mold resistant a product says it is.  If the material does not get a chance to dry and is not exposed to sunlight, mold can grow on almost any surface.  So lets talk about some of these systems.

Acoustical panel systems are by far my least favorite of the systems.  These semi rigid fiberglass panel systems were originally designed to be acoustical panels to reduce reverberation in large spaces such as gymnasiums and movies theaters.  And as in their product name, they are panel systems, and there is no hiding that.  So aesthetically it does not cut it for me.  However, due to their nature, they do have an insulation quality to them, but like fiberglass batt insulation, it insulates by trapping air within the produce to slow the heat transfer.  However, they do nothing to stop moisture migration.  This is a good and bad thing at the same time.  Because in even dry basements, there is still small amounts of moisture vapor moving through your wall, and if you read the article posted above, you will now know that you want your basement walls to be able to dry to the interior, which this product will allow.  However, if there is large amounts of moisture movement, it could possibly condense within the product, getting it wet and potentially causing mold growth.  Therefore it would be wise to leave a small air gap behind the system to allow a free flow of air to help dry the system out if it does happen to get wet.

Rigid foam panel systems I believe to be a much better solution.  The foam panels will typically have a higher insulating value per inch and help to prevent future moisture problems much better than the acoustical panels systems.  However you want the foam panels to be applied directly to the foundation wall.  You do not want the 1″ gap between the basement wall and wall system as some of the installers recommend to run plumbing or electrical wiring.  This air gap leaves a place for the moisture moving through your basement walls a place to condense, especially since the temperature of the basement wall will now be colder because of the new insulated wall system.  It is a better idea to cut in a chase into the foam behind the finish to run this equipment.  The foam panels will still allow your basement walls to dry to the interior, however I would be leery of a vinyl wall covering.  In the commercial building sector, especially in hotels, vinyl wall covering has been known to cause severe mold problems unless there are micro perforations.  However just like the acoustical wall systems, they are a panel system, and it is hard to hide that fact.

Conventional framing and drywall finishing is perfect for the DIY’er and an option that will help to seamlessly blend a new lower living level with the rest of the home.  However there are some things to consider when framing up against a basement wall.  You want to apply a 1-2 inch rigid foam panel directly to the basement wall before framing any new wood or metal walls.  This foam layer provides the necessary thermal barrier as well as moisture control that is provided by the rigid foam panel systems.   The additional framing can be used to run all your utilities such as plumbing and electrical wiring and gives you the structural members to hang a TV and any other miscellaneous items as well as space for additional insulation.  However it is wise to apply a capillary break below your new framed walls in the basement as I mentioned in one of my earlier posts about a sill sealer that helps prevent any moisture from the basement floor to migrate into the framing.  And as mentioned in the article, basements are inherently moist areas.  That is why I recommend a paperless drywall product that using a fiberglass mesh facing instead of paper, removing the food for mold and increasing the durability.  I used this product in my own home as well as modified the wall system by using 2×3 framing members and holding them an inch away from the wall and filling the cavity with an expanding spray foam insulation.  I will explain my choices in a future post.

Now the article referenced at the beginning of the post mentions installing carpet, which I would not recommend installing directly to the concrete floor (especially a carpet pad).  Older homes never installed a vapor barrier below the basement floor, which obviously allows moisture to move through the floor into the carpet.  Most local hardware stores now sell a sub floor product that is a 2′x2′ sheet of plywood with a plastic coating and feet underneath that leaves a small air gap allowing any water to run to the floor drains below the floor without ruining the surface.  In this case, you can install any type of floor material, including wood.  However if you don’t want to have the additional expense of the sub floor system, then I always recommend a solid flooring material such as tile or linoleum.

Well I hope I did not overwhelm you, but at least educated you a little more about what may be going on behind your walls.

Now I would definitely not expect to be invited (not this year anyways) to such a note worthy week of learning on the latest thoughts in the world of building science and elbow rubbing of the industry leaders.  But I would have to say that for someone who is moving into the industry, this would be a great confirmation of one’s work and contribution to be invited.  So for the time being I will have to be satisfied with the fact I was able to attend one of Joe’s great lectures and pick his brain at breakfast, as well as work with his partner Betsy Pettit on Ohio’s only LEED Platinum home.

Like Allison Bailes from Energy Vanguard, we will have to sit in our office glued to the computer screen watching as the tweets (#bscamp) come in from its attendants about some of this week’s topics such as spray and foam board insulation, IAQ etc.  So if you’re interested to know more about the Building Science Summer Camp, check out the Energy Vanguard blog post (I Don’t Need No Stinkin’ Building Science Summer Camp!), as Allison pleads his case for an invitation to next year’s event.  Or do as we do and check out some of the thousands of papers that Building Science Corporation has published and posted to their site, free of charge.  It is a great resource for some of the industry leading research for building performance.

-Josh

RR-0202: Basement Insulation Systems

by Building Science Corporation

The Problem

Meeting Energy Star levels of performance is one of the criteria for constructing homes to Building America levels of performance – levels defined by the Building Science Consortium and others.  Homes constructed with basements require some degree of basement insulation to meet Energy Star.  As a result all Building America homes with basements constructed by the Building Science Consortium have basement insulation.
In any event, heat loss from basements accounts for such a significant portion of the energy loss from a home that it is clear that a home with a basement must have basement insulation to be called “energy efficient.” Additionally, in many jurisdictions, basement insulation is a building code requirement.

Finally, most homeowners with homes with basements finish the basement area for additional living space.  When they do, they typically insulate the perimeter walls.  Homes with basements often end up with basement walls that are finished and insulated.

There are only three ways to insulate a basement wall: on the interior, on the exterior or in the middle.  Of the three,
the most common approach has been to insulate basements internally.  The reasons for this have been due almost strictly to cost.

Continue reading the article at buildingscience.com

Posted by Mark Piepkorn via BuildingGreen.com

From the website of The Carbon Neutral Curriculum Materials Project:

The Carbon Neutral Curriculum Materials Project is a joint research effort between members of the Society of Building Science Educators, the American Institute of Architects, and a private donor, the purpose of which is to provide practitioners, faculty and students with the means to meet the 2030 Challenge — that is, to be able to design and construct buildings to a state of carbon neutrality by the year 2030.

Continue reading the article at BuildingGreen.com LIVE:

Don’t Try This At Home:  Armchair Building Science.

By Peter Yost via GreenBuildingAdvisor.com

Is the mold on the plywood in this attic the result of inadequate attic ventilation or air leakage?

The homeowners called me after a certified home inspector stated the former; that the attic was underventilated and moisture was building up as a result. The roof assembly had soffit vents at the eaves and two gable end vents. Not as effective as ridge-to-soffit ventilation, but probably close to building code requirements (see Green Basics – Attics).

I did not have the time to get down to the home to take a look myself, so I asked the homeowner to send me photos of the house and the problem. Bit dicey to diagnose a problem and give guidance over the phone based on a short series of photos, but armchair building science is an honorable pastime.

Continue reading the article at GreenBuildingAdvisor.com

BSI-001: The Perfect Wall

By Joseph W. Lstiburek

The perfect wall is an environmental separator – it has to keep the outside out and the inside in.  In order to do this the wall assembly has to control rain, air, vapor and heat.  In the old days we had one material to do this: rocks.  We would pile a bunch or rocks up and have the rocks do it all.  But over time rocks lost their appeal.  They were heavy and fell down a lot.  Heavy means expensive and falling down is annoying.  So construction evolved.  Today walls need four principal control layers – especially if we don’t build out of rocks.  They are presented in order of importance:

• a rain control layer
• an air control layer
• a vapor control layer
• a thermal control layer

A point to this importance thing here, if you can’t keep the rain out don’t waste your time on the air.  If you can’t keep the air out don’t waste your time on the vapor.

Continue reading the article at buildingscience.com

BSI-009: New Light In Crawlspaces

By Joseph W. Lstiburek

Crawlspaces stink, they rot, and are just plain icky.  Photograph 1 shows the modern crawlspace, which is a forest of water droplets on the underside of fiberglass batt insulation.  The exposed wood floor joists are rotting.  The house over this crawlspace is not shabby.  Did I mention that this is a vented crawlspace?  Oh, by the way, there is a continuous plastic sheet ground cover and excellent drainage.  Everything in this crawlspace was done “right.”  It has code specified ventilation, a continuous impermeable ground cover, excellent drainage and still we have a mess.  What caused this mess?  The floor insulation.  No way.  Yup.

Photograph 1: Icky Crawlspace—Note the condensation on the underside of the fiberglass insulation and the rot at the exposed portions of the crawlspace floor joists.

Continue reading the article at buildingscience.com