Attic dropped soffit air sealing

[alxlab]

Bought my first house 6 years ago and it's been non stop major renos since then. Had to demo the whole finished basement and redo the french drain around the house but that's a story for another time. Today I'll just share a "little" project I'm currently working on to help heating bill and comfort in my home for the upcoming winter. So you may be asking what a dropped soffit is. Here's the dropped soffit in my bathroom:

Basically it a part of the ceiling that has been lowered. In this case where the shower and where the vanity is. Above this is the attic which is unconditioned (freezing in the winter and hot in the summer).

If you already have experience with house construction you probably already see what the potential problem with this is. Basically where the ceiling has been lower, if the builders were lazy they would not seal the soffit and all the nice warm and cold are will go in between the wall framing around the soffit. Guess what the builders did at my house ? You got it! They didn't seal it! On to of that the a hole straight from the attic to the basement where the tub drain is and main plumbing stack so I can feel cold air from outside go straight to the basement. Not only is this bad for heating/cooling bills, it causes mold due to condensation and low humidity levels in the winter.

Here's an infrared picture of the soffit with temperature currently set to ~70F/21.5C inside. The temperature outside is currently 37F/3C.

59F/15C after taking a shower. That's not good... not good at all...

So how to fix it? Well I could destroy the soffit, insulate it and then rebuild the bathroom ceiling. That's messy and don't want to destroy my bathroom ceiling. The next option is doing the air sealing in the attic. This is the usual method done by the air sealing companies.

Luckily I already installed lights in the attic with a partial wood deck. It's still no fun. The attic is cold, full of fiberglass insulation (bad for the lungs and makes you itchy), nails/screws sticking through the roof and mouse poop since the previous owner loved feeding the birds (the mice love bird feed).

Yeah look at that wonderful sight. Guess where the soffit is? If you guess right at the edge of the roof where that light is you are correct! Got to work on my belly for this one.

To be continued...

 

[trag]

Good luck.

Back in 1998 I spent two weeks in the attic during the holidays stringing a half mile of cat 5 and coax cable through the house and dropping it down inside the walls.

But these days, my main thought when I consider attic work are the immortal words of the character Roger Murtauch, "I'm getting too old for this..."

 

[alxlab]

Thank you Yeah this would be the fourth time doing work in the attic. The first time was just cleaning up the mess left by the builders, adding the path down the middle and putting in the lights. It was well worth it since it makes it a lot easier to get around at least.

 

[alxlab]

This used to be a plastic vapor barrier and the paper backing of the soffit's drywall. Now it's just a crumbly and moldy mess.

Mmmmm roof sand, bird feed, mouse poop and mouse nests. Nice.

Had to clean up all that mess, patch the ceiling and paint it to give some kind of protection.

Want to move the electrical to be able to put the 3" foam board in the wall without spray foaming it in since I want to both the master bathroom vanity light from the wall to the ceiling and I don't want to have to remove the foam to access it later.

 

[Certificate of Excellence]

Oof, home ownership is the ultimate money pit. I just got done knocking down a wall downstairs to open up my wife’s office. Ended up redoing window soffits, fix some house settling cracks, painting, new hardware, refin air duct in/outlets, new carpet, new lights, ran new cat5 &installed new blinds.

… this week I’m refreshing the kitchen- pulled up the floor tile a couple weeks ago & will extend wood floor through out. Remove ugly wallpaper trim, paint walls, Gray refin on bottom cabinets, white refin on top, new butcher lock counters, new hardware, kohler farm sink, relo fridge to south wall and build additional pantry space in its place. Install pan rack over west window.

BUT, I did not have to deal with nasty mouse poop or mold. Well found mouse poo out in the garage but no pests in the house except a few scorpions and centipedes (normal summertime critters around here) which I capture and release outside.

 

[alxlab]

Yeah my house is like Pandora's box. The house looked ok when I bought it. Once I started checking what was hidden behind the walls all hell broke loose lol

 

[RetroViator]

Back in 1998 I spent two weeks in the attic during the holidays stringing a half mile of cat 5 and coax cable through the house and dropping it down inside the walls.

But these days, my main thought when I consider attic work are the immortal words of the character Roger Murtauch, "I'm getting too old for this..."

I have a dream of pulling out the coax run inside the walls of my house and replacing it with Cat6, but there is so much insulation in the attic, it would take a while to dig down and find anything. Other than getting hardwired connections throughout the house, my goal is to run things down to the basement, where I can install a nice little wall-mount rack unit.

It's getting cooler now, so I suppose I could start poking around up there, but... I'm also getting too old for this.

 

[Certificate of Excellence]

I have a dream of pulling out the coax run inside the walls of my house and replacing it with Cat6, but there is so much insulation in the attic, it would take a while to dig down and find anything. Other than getting hardwired connections throughout the house, my goal is to run things down to the basement, where I can install a nice little wall-mount rack unit.

It's getting cooler now, so I suppose I could start poking around up there, but... I'm also getting too old for this.

Well, at least the cable is already run so all you have to do is secure the cat6 to the end of the coax and yank the coax out and along comes the cat6 right behind it. I am actually thinking about utilizing the power lines in my house as a networking solution. The South end of my house has cat5 fished around but the north end does not, so I am considering dumping all of that and using a modular house powerline network solution. A lot less work and aches and pains from crawling all over ones home anyhow.

 

[RetroViator]

I am considering dumping all of that and using a modular house powerline network solution. A lot less work and aches and pains from crawling all over ones home anyhow.

You know the speeds possible from powerline carriers technologies today? Back in the day, I thought they were fairly slow, but I’m sure things are better now.

 

[Certificate of Excellence]

Every Powerline/HomePlug maker claims their adaptors can carry data at speeds of 500Mbps at the entry level models up to 1,000Mbps and 2,000Mbps for the fastest models.

 

[alxlab]

Probably gonna do Cat6 at my house at some point but gonna try from the basement since the ceiling is gone already. It will be easier from there since all the walls have fire blocking which would need to be drilled through if I went from above.

Dunno if it's standard for your area but my house has 1 or 2 fireblocks in between the wall studs.

 

[Certificate of Excellence]

That is how it is in my neck of the woods. Fireblocks are required between floors and a pitched roof. As I have a flat roof, I dont have to worry about that but I do have three floors as my house is that goofy 70's split level design (lotsa stair exercise anyhow ). Running up from the basement makes great sense to me. I assume it is unfinished, so you can attach directly to the joists then up through the floor? Unfortunately, my bottom floor is finished off, so Id have to cut into the sheet rock and through those fireblocks to install. That is why powerline networking is so appealing to me. I've already knocked down two walls on that floor, patched up and painted so am keen to be done with that area. I have zero desire to cut up my ceilings down there.

 

[displaced]

Looks like an arduous bit of work, but that thermal image really shows how much it’s needed!

I really enjoy seeing posts (usually in Facebook groups) about US building construction. Almost everything here in the UK is brick and/or stone with external cavity walls, often pumped full of insulation.

…which sounds nice, but what we gain in solidity we lose in ease of running cat6 everywhere!

One thing is universal though — attic insulation is truly horrible stuff to work around.

 

[alxlab]

That is how it is in my neck of the woods. Fireblocks are required between floors and a pitched roof. As I have a flat roof, I dont have to worry about that but I do have three floors as my house is that goofy 70's split level design (lotsa stair exercise anyhow ). Running up from the basement makes great sense to me. I assume it is unfinished, so you can attach directly to the joists then up through the floor? Unfortunately, my bottom floor is finished off, so Id have to cut into the sheet rock and through those fireblocks to install. That is why powerline networking is so appealing to me. I've already knocked down two walls on that floor, patched up and painted so am keen to be done with that area. I have zero desire to cut up my ceilings down there.

Yeah my basement is unfinished. If it was finished I'd be looking into alternatives like powerline networking or wifi. Wifi at 5Ghz is pretty good since microwave won't interfere with it but usually need to put a few repeaters. Wifi 802.11ax / Wifi 6 looks really nice though. Especially the 8 x 8 MU-MIMO for multiple devices.

 

[alxlab]

Looks like an arduous bit of work, but that thermal image really shows how much it’s needed!

I really enjoy seeing posts (usually in Facebook groups) about US building construction. Almost everything here in the UK is brick and/or stone with external cavity walls, often pumped full of insulation.

…which sounds nice, but what we gain in solidity we lose in ease of running cat6 everywhere!

One thing is universal though — attic insulation is truly horrible stuff to work around.

I actually live in Canada but it's very similar to the construction in the northern US. Yeah the US and Canada have no lack of cheap wood (used to be cheap before covid lol) so that's what's being used mainly. Also it has a lot less older type building which were traditionally masonry like in the UK and Europe. I also had a coworker from Germany that found it strange that we use such a weak materials like pine and spruce in construction vs masonry and metal.

 

[Certificate of Excellence]

I have three networks - a 802.11n 5ghz for streaming/TV/games in the den, 802.11n 2.4 for broad access (when Im out in the yard or on the north end of the house) and a 8.02.11b/g ape for my legacy mac/pc boxes. You are absolutely right about 5g networks, they're great if you're close to the router but have zero range.

Also, while wifi is super convenient, the idea of a wired network (whether it be cat or powerline) seems more secure to me. All this costs money though and Im focused on my kitchen at the moment so all funds on deck for that. Powerline is way down the totum at this point.

 

[alxlab]

So I moved most most of the wires from the electrical box in the wall into another box that will be accessible once the foam board is installed.

There's the wires going tot he box in the wall from the attic.

Had to cut a bigger hole in the bathroom vanity light box in order to access the wall electrical box.

Undo all the wires with the power off of course . There's a tool that will detect if power is still going to the wires without having to touch the wires. A must have for doing electrical work.

That's the con-contact power detector I have. It beeps when it detects live wires.

After carefully removing the wires from the old box and putting them in the new one, I can now put a foam board in the wall and spray foam it without having to worry about having to remove the foam board in the future to access the wires.

Next is to continue installing and cutting the foam boards.

 

[Certificate of Excellence]

Nice job. Those hot wire detectors are invaluable. I have one on my toolbelt. No one thinks about how destructive a 110 outlet can be until you witness an improperly grounded old AF, out of code box arch to a pocket knife and literally burn a hole clean through the blade like a welder. My grandpa was an electrician and his ET buddy blew off his middle finger from dusty, poorly grounded 220 while installing a big business sign in the mid 80s. It was just dumb luck that the arc did not go downthrough his heart to ground and kill him. He'd always say, "Respect them 'lectrics" (midwestern Ohio country boy accent) and he'd show you his hand. Anyhow, my task has been much more mundane. I am knee deep removing this hideous early 90's kitchen wallpaper the previous owner put up. What a woofy, messy job - cant wait for it to be done. In perfect money pit fashion, while pulling the paper down, I discovered the west facing kitchen wall/ceiling joint does not come together - there is a 1/8 to 1/4 inch gap that I have been filling in as I take the wall paper down (wonder how much heat has escaped through that gap). Pain in the ass, and frustrating to find such half-assed shoddy workmanship, but I'm fixing it as I go so whatevs it needs to be done. This piecemeal facelift will eventually get done and the wifey will be happy. Next week I texture and paint the walls and start the refinish work on the cabinets.


Once you get your insulation and cabling where you want it, do you have plans to ever finish off the floor in the attic so you can move around freely? Stick the kids up there when they are unruly?

 

[alxlab]

Yeah you can never be too safe when doing any kind of work. Definitely respect the dangers of electricity. Same for power tools and general safty around a job site (nails sticking out, glass, sheet metal, etc). Been shocked a few times with 110V but nothing serious and done some other stuff that after i was like "That was really dumb". Wearing safety glasses, proper work boots and gloves area must.

The safety boots have saved me from nails through the foot at least a couple times. They also provide insulation when doing electrical work and have a cap at the end to help protect from crushing injuries.

The glasses have also saved me several times from flying object while using power tools. Especially when using circular saws and rotary tools.

The work gloves I wear are just nitrile gloves. They don't have the same level or durability and protection as the leather or material work gloves but keep your hands clean from all the chemicals, glues and dirt. I don't like the lack of tactile feedback from the thick work gloves and reduced dexterity. I guess if I wore them all the time I might get used to it.

 

[alxlab]

I realized that I haven't talked about the tools too much which is actually very important. It helps you do a good job, makes your life easier and is safer than doing workaround.

A lot of people avoid buying tools because they can cost a lot of money, but don't consider the cost of the time wasted no having the proper tool and the cost of having someone else doing the work. Often buying all the tools for a job can still be cheaper than hiring a contractor to do the job. Tools can also be reused for other projects in the future so the actual cost of the tool is usually spread over time. Food for thought. Of course if your not interested or comfortable in doing your own renovation then just hire a contractor.

Now then onto some of the tools I'm using for this job.

Here's a the 4 foot long t-square I use for marking the cuts on the 3" EPS foam board insulation I'm using. 4' is perfect since most panel building materials like drywall, plywood, osb, etc are 4' wide. This tool will guarantee you will have a straight line if you use the straight edge of the board as a guide. It also has a ruler so you can mark the lines at the right length.

This is the 4 1/2" circular saw I use to cut the foam boards. It connect to a shop-vac so all the foam dust gets sucked up. You can use a knife but the cuts are less straight and makes more of a mess. I'm just using a standard rip saw blade.

When I need to finish inside cuts I use a standard steak knife. Cuts pretty well through the foam board.

Here's two type of spray foam I've used to seal around the foam board and to fill other gaps and cracks.

The one on the spray foam on the left left comes with a dispensing straw and is only meant to be used a couple times and comes in smaller quantities.

If you do a lot of spray foaming then you want a spray foam gun like on the right. You attach spray foam cans to it and it has a nob to control the flow of the spray foam coming out. You can also use the nob to close off the nozzle of the gun so the spray foam can be store for months. It's less wasteful than the other type.

I bought the one on the left since I wanted a maximum expanding spray foam for some extra large gaps but they didn't have the cans for my gun.

Hope this sheds a bit of light on how the work is being done