1840 Home, Timber frame, remodel Heating/Cooling/Electrical
Good morning,
My wife and I have owned a 1840 three story home since 2006. We moved out due to job relocation back in 2015. We took this as a sign to remodel the home and bring it back to what it once looked liked.
So here is the back story, I will keep it brief. The house since 1920 has been sold so many times that it should be a Guinness record. We are the first owners to own the house longer than five years since then. The house has been remodeled a lot. Some plaster remains, drywall on top of drywall, knob and tube wiring, cloth (2 pair) wiring, Romex wiring are all in the house. Service was upgraded to 200 amp in 2005. The house was split at one time into two apartments. In 2004 the flipper that bought the house took the separating walls down and tied the 100-amp service for the upstairs apartment into the 200-amp service on the first floor, which is also a sub panel off the main panel next to the meter outside. A heat-pump was installed with 11 registers on the first floor and 4 on the second and none on the third. All by the flipper. We have four fireplaces, two chimneys. The house is on the National Historical Registry, which we found out when we started the renovation.
We have gutted the first floor down to the frame. We did gut, insulate, and rewired the third floor. The roof was removed and replaced in 2013 with DOI approved architectural shingles. The four dormers had the clapboard siding removed. OSB, house wrap, and vinyl (DOI approved) was added. The third floor will need new windows. Currently has no AC or heat.
Total square footage of the house is 2600 sqft. First floor has 12 foot ceiling. Family room is 256 sqft, dining room is 224 sqft, hallway is 300 sqft, kitchen is 352 sqft. There is a side room that is 168 sqft. second floor has two bedrooms. with 8 foot ceiling. 1st bedroom is 256 sqft, second bedroom is 224 sqft. hallway on the 2nd floor is 300 sqft. There are two full bathrooms one on the send and first floor.
My dilemma. The heat pump installed is a 5-ton unit. The duct work is not insulated. Windows need to be replaced on the first floor. Still has wood windows with weights. Framing is true 4X4 and angle beams are 10X4X12. All framing is pegged and slotted. No outside sheathing or wrap. Clapboard on frame. I want to add R30 X 2 for an R60 rating in the roof above the kitchen. The first floor has no insulation and we wanted to use R30 unfaced but that would compress and I would lose the efficiency of the R-30. We plan on sealing the sills to prevent air from the crawlspace entering the hone. However, this has its own concerns with airflow and drying the wood when it gets wet. House is located in southern Va. Do I replace the heat-pump, with mini splits and do I remove the sub panels and go to a one panel system? What is the best way to insulate the walls.
I love this house for the history and want to bring back to what it looked like once it was completed in 1840 (It was started in 1798 as a one room home)
But with some modern features that don’t take way from the original look.
Thanks, if you made it this far in reading. Sorry I didn’t keep it brief.
John
Everything I do has to be approved by the DOI and as a homeowner not an organization I am normally at the back of the line for package approvals. The roof alone took three years. Hence why it has taken so long to remodel the house.
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Replies
"Do I replace the heat-pump, with mini splits..."
I see no reason to do this. If oversized, replace at end-of-life with a better sized one.
A mini-split is a heat pump by the way! It's a confusing, meaningless term.
With old houses like this you can run into issues bringing them up to code with insulation and air sealing as the exteriors are not generally super water tight, and eliminating the energy flow also eliminates the drying. I think if you are fully bring this up to snuf with modern day energy codes you should really think about how well the exterior is waterproofed.
I think your best choice of insulation would be high quality cellulose because it handles moisture fairly well. I agree that there is little indication to replace a functioning heat pump, though you could add ducting to make sure it is properly distributed. There is no reason to replace your sub panel, this would almost be a step backward as additional wiring will be much easier if required.
I would replace all knob and tube wiring, especially if you are adding insulation to the space.
The Heat Pump that we currently have is 19 years old and hasn't been ran since 2018. So, I fear that will need to be replaced or at least looked at to make determination. The ducting will need to be replaced regardless. There is a lot of rust on it and one end is completely open to an exterior wall. Someone placed hvac duct tape over the opening. We did have an idea of moving the inside unit to the third floor and run the duct work through the knee walls and down a cavity to the first floor where there already an opening. The cavity is pre-existing. It was part of the house. The third-floor duct could heat/cool the third and second floor.
The siding, I think I have an idea for so let me run this by y'all.
We add 2" furring strips to the outside framing members; Add foam-board on top of the furring strips. Then add insultation over that. This will create a 2" air gap between the siding and the foam board allowing air to flow.
Electrical will be upgraded to Romex. Why keep the sub panel on the 2nd floor; make it easier for the runs? What about water heaters, tankless or tanked? We have no gas so it would need to be an electric unit..
Thanks for the quick responses. We are drafting our plan for the spring and summer of what work we will be completing.
I'd replace it with another ducted unit, they're the best solution. If you need to extend coverage and can't run additional ducts, then add a ductless unit for those spaces.
Tankless units are low performing options that should only be used when you have no floor space. You can get a resistance tank that's equivalent efficiency with higher performance or get a heat pump water heater that'll be 3-4x more efficient than tankless or electric resistance tank. Tankless units are always a last resort. Ideally, around 1% of homes might have them: picture an studio apartment of 200 sqft. That’s their place.
There is no reason (and actually a few reasons not to) have an air gap in the middle of your insulation, assuming you are insulating the cavities. You want the furring strips/ rainscreen right behind your new siding, with all insulation toward interior of this. I would remove your siding if you are adding to exterior and add sheathing, or barring sheathing attach rigid directly to stud for nice even plane. Or, if current siding is flat, attach rigid insul direct to that.
I hope I understood your proposed assembly, one note, a picture, even poorly drawn, is worth a thousand words….
Here is what we are thinking with the insulation.
That makes much more sense, I did not understand your layers. That is a good wall build up, you may still consider cellulose on interior side of rigid but doesn’t matter that much. Here is a video showing a better way then using furring strips to air gap
https://www.finehomebuilding.com/project-guides/insulation/rigid-foam-vent-baffles
Edit: also you could fur out the interior wall with rigid insulation strips, like a bonfig wall
Thanks for the reply. Doing it like the video will save on cost. I had to look up what a bonfig wall was. That will be a great idea to help build up the wall, so the R-30 doesn't compress.
adding the furring strips will change the look of the exterior. The relationship between face of glass and face of siding would seem to be one of the important things to maintain. doubt that would be acceptable to the AHJ.
seems like getting a continuous air barrier between interior and exterior would be a more primary goal than adding insulation. you can get air barrier and vapor permeability in a few different ways. 30# felt stapled to the back side of the bays with judiicous edge sealing might be a promising avenue -- at least that way you are working within NPS spirit of reversibility.
An important question is whether you want to expose the timber framing, or plaster over it in keeping with the original form of the house.
For the walls the DOI have allowed drywall with mud over the drywall to mimic the look of the plaster.
The plan in post 7 is great if you are doing the labor yourself if you are paying someone it will get very expensive very fast. Note every room of the house just got smaller and the original details just got destroyed.
You must be very careful this house survived because moisture had found a balance point in that whatever moisture that was getting in was able the evaporate and get out before anything got moldy and rotten. You can’t just change one side of this equation without risk.
If you go around and insulate and stop the heat from flowing thru the wall the liquid water that has always gotten in will no longer evaporate as quickly and things could get moldy and rotten.
If you go around and air seal the walls stopping the air from leaking thru the walls and carrying away the moisture things could get moldy and rot.
You simple can’t have modern insulation without modern air and water barriers.
Walta