Real Estate Matters – April 2017


Insulation Science
I recently had the not awesome experience of staying in a hotel room with no soundproofing between the walls. Lying there, really wishing I had earplugs, I started to wonder if there’s a difference between soundproofing insulation and temperature-regulation insulation. And how do they put in insulation in a house that’s already built? Do they have to tear up the walls? How about floors? We know how Capitol Hill ground floors are freezing in winter. Can they shoot insulation into crawl spaces, or does that invite critters?

Back at home I called up Max Grove of Max Insulation and found out there’s a lot more to insulation than I thought. Insulation installation is not just blowing stuff into the walls. It’s a science that takes moisture, air flow, combustion, and air quality into consideration.

How this works, at least with Grove, is that he first identifies the problem. Say a room or a side of a house is cold. Why? Grove uses an infrared camera to identify hot spots and cold spots behind walls and in attics, even in attic areas where there’s no access. He also does something with a fan outside the house. He walks around with the infrared camera, identifying where the cold air comes in and the warm air leaks out. It sounds like an episode of “Ghost Hunters,” but these cold spots can be banished.

Our old homes, as Grove pointed out, were originally built for air flow, which is why we have transoms, for example. We don’t need that now, and what made air flow in the old days now makes our homes inefficient. He explained how the joists abut the brick walls, but there’s a gap, so you can conceivably look down from the attic to the first floor. Those gaps pull the attic air, generally cold and dirty (dust, dust mites, critter waste) right down the walls. There goes your warmth and your air quality. Anyone with allergies, asthma, elderly family members, or small children needs none of that.

If your home is a flip, there’s a good chance that it’s not properly insulated because most contractors don’t have insulation certification, called BPI certification (, based on scientific standards for retrofitting. It’s a whole-house, best practices approach with the science of thermal dynamics, moisture, air quality, and safety. They assess ventilation of gas, carbon dioxide, and moisture – especially from showers, dryers, and kitchen appliances. For instance, in many older homes there is a bathroom that was ventilated by a window instead of a fan. They can’t insulate an attic above an unventilated bathroom because insulation will trap the moisture and breed mold. (Grove’s team will reattach vents that have come loose, but refers contractors to install new ones.)

There are the enclosed porches, bump-outs, and dogleg fill-ins that were almost always poorly constructed when they were built, and probably not insulated. This brings down the efficiency of the whole house.

In a home without a basement there’s probably an uninsulated crawl space. That space traps moisture, making the home clammy in the summer and bone-chillingly cold in winter.

Once Grove figures out where the cold air is coming from – the attic, the walls, and/or the crawl space – he formulates a plan. I was particularly interested in what this means to homeowners. How do you prepare for an insulation invasion? Is it as disruptive as interior painting, which always seems like a good idea until you remember about sanding?

First, bearing in mind that this is Max Insulation – I didn’t survey all area insulation companies – a crew member gets to your home at 8 a.m. for prep. He hangs sheets of plastic to cover the walls, ceilings, and floors. Grove said your home will look like the movie “Outbreak.” Then the rest of the guys get there at about 9:30 and go to work.

If you’re doing attic insulation, they’ll ask that you remove your storage if you have any. If there’s old blown insulation, they’ll vacuum it out. If it’s batting, that pink stuff, they’ll bag and remove it. (There are also homes with old newspapers as the attic insulation.)

Then they fill in the holes with spray foam, such as at those joist gaps against the wall, and blow in a carpet of cellulose, which is a recycled product of paper and denim treated with a fire retardant and an anti-critter chemical. He said it has more R-value (insulating effectiveness) per square inch than the pink stuff, but it’s the same price.

If the walls are poorly insulated, the crew will make a six-inch-diameter hole at the top of the wall. They will figure out where the wall is lacking insulation and what they need to work around, including studs, wires, and window casings. Then they blow in the insulation. They don’t do foam in closed walls because it can over-expand, damaging drywall and wires.

What you need to do to get ready for your wall insulation is to move the furniture away from the walls and have some matching paint ready to go. That’s it. They will make those cuts as needed, but they put them back and spackle like it never happened.

They usually only need to do exterior walls, not walls shared with the next house. If you want to talk about soundproofing, that’s another story. They do that too, but usually for commercial ventures such as the Kennedy Center and between walls and floors of multi-unit Airbnb rentals. That hotel I stayed in ought to give them a call!

If you feel the cold coming up from the floor to your knees in winter, then crawl space insulation can change your reality. Vapor barriers, coupled with a thermal barrier, will keep moisture from coming out of the ground. Grove likened doing one without the other to wearing a down parka unzipped – ineffective.

The work usually takes from 8:00 a.m. to 3:30 or 4:00 p.m., depending on how many areas require attention. The average cost is about $2,000 to $3,000 per region – attic, walls, and/or crawl space. The resulting efficiency is immediate. Expect great savings on utility bills. One of their reviewers on Yelp said he saved 33 percent on the electric bill. If you’re just having insulation done (not as part of a whole renovation), it doesn’t require a permit.

I looked into insulation because I wanted to know more about it. Is there anything real-estate-related that you’d like for me to explore? Email me about it and I’ll work it in. Please indicate if you wish your identity to remain a mystery.


Heather Schoell is a Capitol Hill REALTOR with Berkshire Hathaway HomeServices PenFed Realty and can be reached at, at the office at 202-608-1880, or by cell at 202-321-0874.