Basement framing
Basement wall insulation done the way an upstairs wall is insulated is how you end up with mold behind brand new drywall.
The short answer
A foundation wall dries inward, so nothing goes on it that traps moisture in the assembly.
Insulated walls stop the basement feeling like a different climate to the rest of the house.
Rigid board will not sit flat on rubble stone, so the method follows the foundation.
Four stages, in this order. Each one has to be signed off before the next covers it up.
We measure the real ceiling height at several points, find where the sewer line leaves, and check what the panel has spare. Basements do not photograph their problems.
You get it broken down by stage rather than as one number, so you can see what a bathroom adds or what dropping the bar saves. Free, nothing to sign.
We pull the permits through Louisville Metro. Framing, electrical and plumbing go in and get inspected before anything covers them.
Insulation, drywall, paint, flooring and trim, in that order. The final inspection signs the space off as habitable.
An above-grade wall dries in both directions. A foundation wall can only dry inward, so whatever sits against it has to tolerate being damp without holding water.
That rules out a fibreglass batt pressed straight against block. Warm indoor air reaches the cold masonry, condenses inside the insulation, and the batt holds that water against the wall through the whole summer. It is the classic basement mistake and it is still being installed.
Rigid foam board against the masonry, sealed at the seams, then the stud wall in front of it. The foam keeps the back of the framing above the dew point, so there is no cold surface inside the wall for moisture to condense on.
Closed-cell spray foam does the same job in one step and handles irregular stone or rubble walls where board cannot sit flat. It costs more and it is the right answer in older Highlands and Germantown foundations, where the wall is anything but a flat plane.
The rim joist gets treated at the same time. It is one of the leakiest parts of most Louisville houses and it is easy to reach while the walls are open.
A basement that was ten degrees colder than the rest of the house stops being that. The floor above gets warmer too, because the rim joist stops leaking. It is the least visible money in a basement finish and the part people notice every winter.
Insulation goes in during framing, after rough-in passes inspection and before basement drywall in Louisville closes the wall. It is the same stage as the wall layout under basement framing in Louisville, which is why the two get planned together. Boxed duct runs follow the same principle under soffit and bulkhead framing.
A wall assembly that stays dry, a warmer basement, and no surprise behind the drywall in five years.
We insulate basements in St. Matthews, Prospect and across the metro. Get a free written estimate and we will have your Louisville foundation walls looked at before framing starts.
Worth knowing
A foundation wall can only dry inward. Putting a polyethylene vapour barrier on the inside face traps moisture in the assembly instead of letting the wall breathe, which is why that detail is left out below grade.
We stay inside about 20 miles of Louisville so the crew is on site when they say they will be. These are the areas we cover most often.
Tell us what the space looks like now and what you want out of it. You get a written estimate, free, with no pressure attached.