Grandma’s House
This is the story of Grandma’s House…
Grandma’s House works! It isn’t a fancy house, and it may not be a comfortable house for Grandma, but
as far as building science goes, it works. At Grandma’s house, the dry outside air is constantly moving
through it – keeping moisture and odors from building up inside. And, Grandma keeps a pot of water on
the stove, just to keep the humidity level up. And, Grandma lives many years content in her little house
without any problems.
But, Grandma is getting older. And she is getting tired of hauling all that wood. And, right as she is
thinking about how a change may be needed…
Red comes to visit her Grandma. And as all young’uns do, she knows EXACTLY what Grandma needs!
Grandma needs insulation. Red makes her case, shows her the brochure and Grandma calls “Big Mike.”
Big Mike does exactly as he is asked and insulates the attic so Grandma can save money and use less
wood. And Grandma is very happy.
Until Grandma notices a water stain on the ceiling. Oh dear, oh dear… Grandma can’t catch a break –
now the roof’s leaking. So, Grandma calls Big Mike…
And, Big Mike sees the problem right away. When he added the insulation, now, the roof is cooler
because the heat is staying in the house. But, the bad news is, the moisture from INSIDE the house now
condenses and freezes on the UNDERSIDE of the roof when it didn’t used to.
But no worries… Big Mike knows EXACTLY what to do! This house just needs to be air sealed to stop the
house moisture from getting up to the attic… then, all Grandma’s problems will be solved. If only he'd
thought of that earlier... Now he has to remove all that insulation he just put in, air seal the attic, and
replace the insulation.
But, Grandma’s problems aren’t solved… one day, Grandma notices something strange.
Grandma couldn’t see when Red was coming to visit anymore; her windows had too much condensation
And now that Grandma’s house is so humid, there are little spots on her wall. At first, she didn’t notice,
but before long, those little spots have turned into big spots all over her walls… and by now she is calling
Big Mike demanding “WHAT HAVE YOU DONE???”
Well, Big Mike realizes the mold is growing because the walls are wet from condensation. No problem –
we’ll warm up the walls by putting in some insulation.
And the excess moisture? Now that Grandma’s house has been air sealed and insulated, she doesn’t
need that pot. But, to be EXTRA safe… Big Mike has one more idea for Grandma…
We’ll add some ventilation to Grandma’s house… and Grandma, just to be safe, runs that fan A LOT!
But poor Grandma. She notices, when she runs the fan… something is wrong with her stove. And
Grandma learns very quickly, the big fan always wins. So once again, Grandma calls Big Mike…
And once again, Big Mike came back. Big Mike realized the error of his ways… with all the insulating and
air sealing, we were saving Grandma a lot on her energy costs but, in addition to the condensation and
mold, now her stove is backdrafting. With that big fan running, the stove doesn’t draft properly, there’s
just NOT enough air. So, Big Mike installs an outside air feed directly to the stove, and installs make-up
air for the exhaust fan…
And she lived happily ever after. And Red? She learned a few things along the way too… and now she
knows what it really means to Weatherize a house.
The End.