This allergy season has been particularly hard on my family and I. I live in an older home that could use some improvements (including replacing the windows). I also have a daughter that has pretty bad allergies year-round (included common household dust). What are some fairly inexpensive improvements to help keep the dust and pollens out of my house?

Sorry to hear about the allergies MaxPark. This question is commonly treated with improvements to or replacing your HVAC system. I am a contractor that works with various remodeling projects and have heard this request before. First there are ways to clean your furnaces ducts to reduce the amount of airborn dust and other allergic irritants. Depending on what stage of remodeling you might be in or your level of frustration you might want to consider a radiant heating system which will at least limit or replace the time you run your heating system thus reducing the amount of circulated dust in your house.

Removing carpets and using hard floor surfaces.
In addition to the HVAC suggestion above you could add a filtration system to it.

The suggestion to have your HVAC system looked at was a good one. In older homes the duct work can wear down like all products. Making sure the ducts are tightly sealed and the HVAC system isn't pulling in dust and all the other millions of particulants is a good start. The real problem with an older home is getting it sealed up. There is a new type of contractor out there called a "Home Performance" contractor. They come in and run a blower door test and find out where all the leaks in your home are and will work up an estimate to seal up your home. They can test your HVAC system for leaks also.

Everyone wonders why, particularly in the winter time, why there is so much dust in a home, when the windows are kept closed most of the time. I know it's hard to fathom that the exterior walls of a home could allow dust and pollens to get into the home, which is your real problem. Stick frame homes leak like sieves through the exterior walls. How can that be ? It has drywall on the inside, sheathing, building paper and siding on the outside. How does that allow air infiltration with all those layers. An older home (20 years or more) most likely doesn't have the air infiltration paper that new homes are required to have. You would be amazed at the hundreds of penetrations through a stick frame wall cavity. It is impossible to completely seal up stick frame construction new or old unless you use some of the new technologies.

For people who are remodeling their homes and plan to stay in them 5 years or more, we have come up with ways to create a "solid wall" barrier, by applying a one sided SIP, called Insul-Lam directly over the exisiiting siding and then re-siding the home. You did mention that you were going to upgrade your windows, which can be done without residing the home. I wanted to throw out the Insul-Lam technique if you also planned to reside the home. Replacing your windows would be more for better energy performance than helping stop air infiltration, unless your windows are so old they don't seal well when shut or the seals have broken down.

If you were going to invest into residing your home, I would be happy to write more about the "solid wall" application.

Depending on what your long term goals are with your home, what you have to budget for improvements, you could first start out with a home performance study, seal up your home the best you can from that, make sure your duct system is tightly sealed and possibly upgrading your HVAC unit and see how how the home performs. To achieve a completely sealed home, you would have to look into the solid wall application and residing the structure.

The Panel Guy

The Panel Guy,

I can see that an external skin would make siding easier; are there other advantages over putting on a layer of rigid foam?

If I had a two story with 2500sf of siding, 11 windows, and 3 doors, how much would the Insulam add to the cost of re-siding the house if it were in your neighborhood?

What do you do with a side that has a brick veneer?

Very respectfully,
Larry

The advantages of installing the layer of rigid foam is to create the solid wall that a SIP or ICF is. The way SIPs and ICFs function, as solid walls, is that they block heat and cold and air infiltration from permeating through the wall surface from outside elements as well as blocking heat and cold from transferring through the solid wall from the conditioned interior.

The first time we had the opportunity to test our theory that skinning an existing structure would dramatically change the way an existing house would function was on an addition/ remodel project where they were going to build a 1,300 sq. ft. add-on and change out their windows on the entire home. They did mention that the west side of the house cooked in the summer time and the three rooms on that side of the house were unbearably hot unless they ran their air conditioning throughout the day. We suggested the idea of skinning the existing walls and residing. They did not have it in their budget to skin the entire existing structure, so we just did the West side of the structure where the Master Bedroom, a small bath and one other bedroom were located. Due to doing just that side of the structure, they no longer run the air conditioning throughout the day. They say that they run it only during the late afternoon hour and only have to run their air conditioning a couple hours a day. They're saving up to do the rest of the house at some point. Creating that solid wall barrier is the well kept secret that SIPs and ICFs are bringing out into the open. Advanced framing techniques being employed by stick framers who haven't figured out that SIP or ICF construction is cheaper overall, are skinning their structures with a layer of foam over the shear-ply and still insulating the stick frame wall cavities. The point is to achieve the higher R-Values and create that solid wall surface for blocking the transference of heat, cold and air infiltration from either side of the wall structure.

You actually need to know the exterior wall surface square footage to do an accurate cost analysis, but the square footage of the exterior walls do come in somewhat close to floor square footage. The Insul-Lam product with 2 inches of foam (adding an additional R-factor of 8) runs $ 1.20 per square foot. Using the square footage of 2,500, the Insul-Lam would cost $ 3,000.00, throw in accessories shipping and sales taxes and it would cost around $ 5,000.00. Insul-Lam comes in 4 x 8 sheets and installs like regular shear-ply. I would estimate about three days labor, two guys to skin the structure (single story). In my neck of the woods that cost would be approximately - $ 1,800.00.

We came up with the idea of skinning a home, where the siding was so dilapidated it needed replacing, or for those who simply had the money and wanted to reside because they could. The huge savings with skinning the structure with the Insul-Lam product is you don't have to demolish the existing siding. You simply sheet right over it. The labor and the cost to tear off the existing siding or other finishes, clean-up and disposal of the debris, from our calculations, of a structure that we completely skinned and resided, was about 2/3 of the cost I've shown above. The client was able to achieve solid wall construction and reap the benefits of huge energy savings for a few thousand dollars more. The client ran their own calculations from what they used to pay to heat and cool their home to present and figure they will re-coup the additional investment in 3 years or less and they tell us that Molly has put her dust cloth in storage. Not to be taken literally but she did make the point that she only has to dust every couple of weeks now, where before she was dusting every other day.

Brick veneer. Exisiting ? Can't do much with that area outside of attacking it from the interior with injecting the wall cavities with blown in insulation, or as we did on a small area of one home, we cut out the sheet rock in the stone veneer section and installed solid foam to fill the stud cavities. Installing new veneer over the Insul-Lam would require long fasteners attaching the chicken wire so that the fasteners grabbed the stud framing of the existing wall. 4 inch long screws would be needed.

Thank you for all of your suggestions. I will deffinitely get started on my HVAC system.
I am curious about learning more about Radiant Heating. I did a quick search on google and found some info that said radiant heat reduces allergens by 60% - 90%. I am wondering how accurate this information is. Also, I am planning on taking out the carpet in most of my upstairs living areas and installing natural bamboo flooring. Would I be able to put radiant heat beneath bamboo? If so, what system do you suggest? I would like to stay in mid-range products, as I'm sure a project like this is going to be pretty pricey.

MaxPark, you might consider starting a thread in the radiant heating section about the bamboo floor questions.

The Panel Guy,

Thank you for your detailed response.   The 2500 sf was the siding area, so the WAG does apply. 

When you say that you estimate it would have cost 2/3 more to have removed the existing siding (I have classic Al crap), is that 2/3 of the #1,800 labor or 2/3 of the $4,800 total?

Very respectfully,
Larry

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