Adding walkways to unfinished attic under blown in insulation

[DennisDoesEverything]

I'm about to have to run Ethernet cables all over the attic (for PoE security cameras and flood lights). I know from past experience that unless you have the power of flight or have been bitten by a radioactive spider recently, getting around up there is going to be a PITA. Just to get from the top of the folding stairs to the larger attic space requires doing a weird contortionist move in 2-3ft of headspace against a sloping roof with nails sticking out, because for some asinine reason they put the attic opening facing into the eaves of the garage instead of in the middle under the roof peak.

It does open up in height somewhat further in, but there's still challenges like for some reason they continued the slats of the house roof down into the garage attic space, so that when you go to leave the garage attic space into the larger house attic space you're faced with navigating a 45 degree wall (continuation of the house roof slope) and trying to find a gap to fit through. It's as if the garage were added afterwards, but I'm certain the house and garage were built together. Once you get through that, there is a spaghetti of 18" diameter HVAC ventillation hoses and diagonal bracing to get around like a jungle gym.

And all this is done with no floor, trying to find footing on 2ft on-center ceiling joists while swimming in a couple feet of blown-in cellulose insulation like a ball pit. And it's usually 140F in there which is why I waited until Fall to even start thinking about this project. After having put my foot through the ceiling last time I was up there, I'm thinking enough is enough: if I'm going to do this security cameras project my wife wants, part of the materials and time budget is going into laying down some walkways first.

Have any of you done this? I'm trying to decide between long strips of plywood, or wide 2x boards, some combination thereof? I'm not sure if I want to try to get the plywood to go under the blown in insulation, or use boards to build up some height and put the walkways on top, or just make walkways with narrow boards that the insulation can fall through. Also if I use plywood, what is the minimum thickness I can get away with? I'm thinking of getting a nail gun that shoots those long staples (not sure what they're called) to secure plywood to the joists.

 

[Lynden]

I think the first thing you need to do is rethink your attic access location. Is there a closet or hallway inside the house which would be a more convenient location? Access doors can have a frame around them or they can be flush as shown below. They can be disguised to look like something else such as a vent or skylight. Access to the attic can also be from the outside of the house.

 

[Old Man Roger]

I had blown in insulation in my last house attic. I actually put another layer of 2x4 over the existing joists, then put plywood on top of that. That way I wasn’t mashing down the insulation.

My electric bill went down and my whole attic had a floor.

 

[pcmeiners]

"And all this is done with no floor, trying to find footing on 2ft on-center ceiling joists while swimming in a couple feet of blown-in cellulose insulation like a ball pit."

You did not describe your insulation type, I swim in blown fiberglass, a truly wonderful experience especially if sensitive to it.
As to my method of getting around in the attic, I have 2x10 down the middle, plywood bends too much between the joists. I am 6'6", sitting I have to bend my head to get around, a real treat

 

[billconner]

I put down strips of 3/4 ply, and blew my way out with cellulose. Access is via a gable vent. Very easy. I don't expect to go back in, maybe once in 10 years. Cellulose is 20", so 16 or so above ply. I think you may want to build up a crawl walk, not sure. Simplicity over cost working in attic. What can you get into attic? Long 2x12s - or enough to get to top of cellulose - on edge with ply on top? You probably want to distribute load on every joist/lower chord. If you could prefab 8' long sections that just sit in place would be simple.

 

[Old Man Roger]

"And all this is done with no floor, trying to find footing on 2ft on-center ceiling joists while swimming in a couple feet of blown-in cellulose insulation like a ball pit."

You did not describe your insulation type, I swim in blown fiberglass, a truly wonderful experience especially if sensitive to it.
As to my method of getting around in the attic, I have 2x10 down the middle, plywood bends too much between the joists. I am 6'6", sitting I have to bend my head to get around, a real treat

Now that you mention it, I put a brace between the joist every 4 feet to support the end of each piece of 3/4 plywood. I could only get the plywood up there in 2 foot by 4 foot sections. That kept the joists from wanting to twist. I stacked a metric **** done of stuff up there till I got a house with a garage again.lol

 

[pcmeiners]

"I could only get the plywood up there in 2 foot by 4 foot sections."

My ridge board is like 4 feet up, I have a tough time getting 2 by 10s up there. For the fun part, the access opening is in a coat closet. Always nice to have fiberglass in your over coats, especially around the collar area.

"I stacked a metric **** done of stuff up there till I got a house with a garage again.lol"

You have my condolences, that thought will give me nightmares.

 

[isb cornbinder]

I got a deal on a stack of one inch plywood. paid $20 a sheet. rather than installing the required straps to tie the trusses together, the plywood went in.
Since I was the guy who built the garage, I put the attic door close to the middle of the shop.

 

[Old Man Roger]

"I could only get the plywood up there in 2 foot by 4 foot sections."

My ridge board is like 4 feet up, I have a tough time getting 2 by 10s up there. For the fun part, the access opening is in a coat closet. Always nice to have fiberglass in your over coats, especially around the collar area.

"I stacked a metric **** done of stuff up there till I got a house with a garage again.lol"

You have my condolences, that though will give me nightmares.

I had a nice pull down stair case, but the orientation of the rafters made it so I had to rip the plywood.

 

[pcmeiners]

Home ownership is so much fun!! Maybe one of these days I will get my garage together.

 

[bdbecker]

The previous owner of my house was kind enough to leave a pile of random lumber in the rafters of my garage when he moved out. Most of it was junk, but there were a couple of 10' long 2x12's that I ended up installing down the middle to create a crawling path for when I needed to get around up there. I rarely need to go up there, but certainly appreciate having a strong and stable path when I do.

 

[Old Man Roger]

Home ownership is so much fun!! Maybe one of these days I will get my garage together.

I had at least 30 new holes in my head from the roofing nails..lol I could stand up down the middle, but doing the ends near the eves cost me some skin and blood.

 

[thammel]

I went through this whole thing earlier this year. Got fed up with the hatch access, so I installed high quality folding stairs. Then I put up a plywood walkway elevated above the insulation. I did this my nailing up 11" long (pretty sure) pieces of 2x4 at every truss along the 2 foot wide walkway. And then I nailed horizontal pieces of 2x4 to these for good support for the walkway. (By the way, all this nailing was a great excuse for a new Milwaukee 18v fuel framing nailer....sure is a great tool!) This was a hassle of a job but well worth it now.

 

[whateg01]

...
Since I was the guy who built the garage, I put the attic door close to the middle of the shop.

Good call! That was you can stand on the car roof to get up there!

 

[DennisDoesEverything]

It's blown in celluose insulation. Not as itchy as fiberglass at least.

I like the prefab idea. I'm having a brain wave: maybe I can prefab raised walkway sections, with some kind of end fixture that allows pieces to join not on a joist and be strong.

 

[tarmy]

I have always put in a light switch up in the attic at the access door. That way you have a couple lights up there whenever you need to be up there…helps a lot.

 

[Old Man Roger]

It's blown in celluose insulation. Not as itchy as fiberglass at least.

I like the prefab idea. I'm having a brain wave: maybe I can prefab raised walkway sections, with some kind of end fixture that allows pieces to join not on a joist and be strong.

I used deck screws, so I could access anything under the new floor.

 

[DennisDoesEverything]

This is the sort of thing I was referring to in last post. Sort of like interlocking garage tiles but for attic walkway. Being square and more than 2' wide can span 2' joists in any direction, having 4 joinable edges means you can do L, T, and + intersections. Pieces would join by using a mallet to drive two dowels through holes in overlapped joints (total of four dowels). Thin-ish plywood over central square. The 2x4's can be notched easily to make # frame by using a dado blade on my table saw.

 

[DennisDoesEverything]

I think I can fix the entry by flipping the direction my stairs are installed in, although having another entry on the other side of the house wouldn't hurt.

 

[pcmeiners]

I had at least 30 new holes in my head from the roofing nails..lol I could stand up down the middle, but doing the ends near the eves cost me some skin and blood.

On the positive side, at least you can stand up with 30 holes in your head, I can't.

 

[Old Man Roger]

On the positive side, at least you can stand up with 30 holes in your head, I can't.

I'm in a new house now, much bigger attic, but no floor. If I decide to stay, I'll put one up there for sure.

 

[firebirdparts]

Sounds like every attic ever. If you have trusses with a 2x4 bottom cord, then that does create a bit of a problem for your simple version of any flooring. If you have 2 x 6 then it's not so bad. The floor can be over the insulation and you still have a reasonable amount of insulation.

 

[DennisDoesEverything]

Sounds like every attic ever. If you have trusses with a 2x4 bottom cord, then that does create a bit of a problem for your simple version of any flooring. If you have 2 x 6 then it's not so bad. The floor can be over the insulation and you still have a reasonable amount of insulation.

Unfortunately I believe it's 2x4 not 2x6. The builder of this house missed no opportunity to cost cut.

 

[DennisDoesEverything]

Brain wave #2. I don't have to get myself across the attic if I can get the wires across the attic without me.

 

[billconner]

Sounds like every attic ever. If you have trusses with a 2x4 bottom cord, then that does create a bit of a problem for your simple version of any flooring. If you have 2 x 6 then it's not so bad. The floor can be over the insulation and you still have a reasonable amount of insulation.

Not reasonable where I live.

 

[CN Spots]

You just need to get wires from one locations to the other? I see no reason why that can't be fun and dangerous.

 

[Innovate1]

With trusses the bottom cord is usually 2 x 4. Even if the bottom cord is 2x 6 that doesn't give enough space for insulation. When this house was build I put 2 x 4s about 16" up from the bottom screwed to the diagonals of the truss. Then put plywood on top of that. Did all that before the ceiling drywall went up so I could get full size sheets up there. I have a nice walkway down the center. Lowest roof pitch is 6/12 so I have plenty of headroom. I also ran some plywood parallel with the trusses in a couple spots where there were things I thought I might need to get to later. It has been very useful. I did have a comment from a carpenter working on the detached garage a couple years ago about not letting the inspector see it but I didn't have any issue with it - in some areas that would probably be an issue.

 

[pcmeiners]

DennisDoesEverything, I guess I have a warped mind but your drawing looks pornographic.

 

[no704]

Get some snow shoes!

 

[thammel]

Oh, in addition to the insulated aluminum fold down ladder I installed, I put up 12" high walls of 2" thick foam board at the top surrounding the attic ladder hole. Then I put a 2" foam board on top of this for extra insulation. I open the ladder, climb up and move the foam board. And I do have a light switch at the top for the row of 6 lights in the attic.

 

[BurtEggley]

my security guy uses a long fiberglass rod about 15 - 18' long. He lightly tapes the wire to the end of the pole and feeds it in from under the eaves. Then he or another guy goes in with another 15' - 18' long fiberglass rod with a hook on it and snags the wire from the first pole. Together they can reach almost 40' to snag a wire. If the wire is too stiff or heavy he uses light string to snag and pull the cable. Amazing to watch them work.

 

[zak77]

I say just bite the bullet and figure a plan to get as much done in as few trips as possible and walk it up there. I've done quite a bit of work in my attic with a similar setup so i know what it's like. Last weekend i had to put a junction box in which required me to literally swim in the cellulose to get it done. Then i moved on to putting insulation in the attic over the garage. It's attached to the house so the only access is a skuttle in a closet in the middle of the house. So i can only fit so much up at once then drag it 30' to the garage attic then finally get it to where it needs to be. Still have a little more to take care of today to wrap it up but you do what you gotta do to get the job done. Plus a shallow roof pitch(5/12) and being 6' 2" doesnt help

 

[dante2]

my security guy uses a long fiberglass rod about 15 - 18' long. He lightly tapes the wire to the end of the pole and feeds it in from under the eaves. Then he or another guy goes in with another 15' - 18' long fiberglass rod with a hook on it and snags the wire from the first pole. Together they can reach almost 40' to snag a wire. If the wire is too stiff or heavy he uses light string to snag and pull the cable. Amazing to watch them work.

When I did my cables there were 2 pieces of random 20' PVC up there. I taped the cable to the pipe and pushed it to the soffit.

 

[nmk_61802]

You just need to get wires from one locations to the other? I see no reason why that can't be fun and dangerous.

They actually make a few tools to do just that:

https://www.amazon.com/Greenlee-06186-Cablecaster-Pulling-Three/dp/B001HWAGRM?tag=atomicindus08-20

 

[larry4406]

I didn’t read the above so I apologize.

When I had the attic purged, I had framer install 2x10’s vertical (10” dimension) perpendicular to the attic trusses at 16” out to out. This on top of the truss 2x4 bottom chords. Starts at pull down stairs.

After attic was foamed and blown they installed 3/4 OSB on top to create a cat walk.

Works like a dream.

 

[Fav Onefour]

Somewhat similar access to attic.
The walkways don't need to support a whole lot of weight. I used 2x4 uprights to the rafter joists and 2x4 framing for platform.

Granted, I did this before the final insulation. But it's doable with a little hand digging through the insulation.
The eve access opening is terrible. I pre cut the materials and stacked them by the opening. I went up to build the platform at night when it was a little less brutal.

 

[sizem]

Lots of ways to skin the cat depending on your end goal and attic structures. On previous home, attic had 40 inches blown in insulation. I created walkways & storage zone w/ wood composite I beams ( e.g tru joists) & advantech walk surface, filled w/ combo of foam board/batts to equal blown in R value. Resulted in a 20x20 storage area and a 40 x2ft walkway. I had a large pull down ladder system that facilitated the loading of the I beams into the attic after move in.

Current retirement home (approx 30 inches blown in fiberglass) only needs occasional walkabouts. Some areas I have 2x10's where I rake the fill away during a job and rake back.
Typically, I may add a 2x10 only when a specific job comes up.
Other areas require access over large HVAC metal ducts (e.g. 30/20" ducts). In these areas I created 2x4 three sided "U" hung from the upper cords of the truss and I step from one to the other to get to my targeted site.

 

[gregs]

I am needing to come up with a solution to add a walkway to our attic. I am wanting to air seal and add blown in insulation this winter. The bottom cord is a 2x6 with a 4:12 pitch roof. There is not a lot of space up there and I am not looking to add any storage, just from the access spot to a walkway going to both ends of the house for any future work. Also not a lot of space to get large pieces of material up there. Also my trusses are the typical style with all the cross bracing and its a hip roof, so the valleys are full of structure.

I was hoping to come up with some type of prefab sections that I could build in the shop and then bring up a section at a time. I want to make it elevated for the added insulation but not sure how to get the blown in under the walkway. Any other pictures or suggestions would be great.

 

[rharman]

I've had this in mind or YEARS but never pulled the trigger.....

https://www.amazon.com/Attic-Dek-Flooring-Installation-Organizer/dp/B07GX5CCHR?tag=atomicindus08-20

 

[Old Man Roger]

I've had this in mind or YEARS but never pulled the trigger.....

https://www.amazon.com/Attic-Dek-Flooring-Installation-Organizer/dp/B07GX5CCHR?tag=atomicindus08-20

From the video, it looks like it sits on the drywall?

Edit. Just watched an install video, it does go over the joists, but that stuff looks flimsy as hell.

Doesn't look like it would make it through many Florida summers, looks like it would get brittle and fall apart.