AFTER... I punch holes through the knee wall...

Two questions:

1) Do you have access to the area behind the knee wall (and can you fit back there) to install your roadbed, lay track and wire it?  Also you need to be able to get back there in case of a derailment.

2) Is the area behind the knee wall insulated?  If the finished, insulated area stops at the knee wall then the space behind the knee wall will be very hot in Summer and/or very cold in Winter (depending on where you live).  This heat or cold will enter your room via the tunnel portals.  You could make some foam rubber plugs to block the portals when not running trains.  

Bob,

Second question first... I live in New Orleans and Yes, the roof & knee wall are insulated.   I built the viaduct out of two pieces of 2" foam glued together... so, 4" foam which I am going to use as plugs. I guess I paint the plugs black so the portal looks like a tunnel?

Further up in the apartment (in the bedroom) there is access to the heat ex-changer.  It's a brand new heat pump unit... so, I've spent some time in there.  I intend to make two access cutouts under the layout at the entry/exit points to improve access.

Thanks!!!

  Recent problem I have is the cat saw the portal and realized it’s a portal to new territory!

Sure, go nasty up the drywall.  Consider running the middle loop through the wall too.  Small curves should be enlarged when ever they can in my world.

I like it Dennis. I would suggest adding a guardrail along the outside of the platform in the back too. Humidity issues may give you fits with the track in unconditioned space.

Let us know when you annex the space.

Bob

Thanks Bob... yeah, New Orleans is a tad humid I guess we will see how Atlas's assurance of their indoor/outdoor durability holds up.  I suppose I could have the heat pump temper that area as well... it's not much space and the duct runs right though the middle of it.  The thing is super efficient and cheap as all get out to run.

Whoops... YES, on that guardrail!!!

My first thought was Bob Bartizek's first question.  We lived in a house when in our 30s that had bedrooms in a similar space and had storage behind the knee walls.  I found it easy to crawl back there for storage and also to fix a wiring issue the electrical novice before me created.  Today with a fake knee and damaged nerves in the other--no way!  Would you be able to roll around behind the knee wall if you end up in a similar condition as me?  I need to get a roll around solution for our low attic now that I can't crawl in there anymore.

If you can envision maintaining it as you get older, then get out the sawz-all and have at it!! 

I envision a "tunnel" behind the knee wall made up of 2" (or more) foam cut into long "planks" and then glued together to form a long skinny box (tunnel).

Mark,  Good point!   I'm still in somewhat decent shape (too fat though).  I think I should be good for a while and my son is only a few blocks away.   I have been thinking about soldering the rails and I don't run my trains very fast.  If I have to go in there two or three times a year it should be fine... if I have to go in once a month ...that could be an issue.

The roofline looks very steep, I'm going to assume you checked and know that you have sufficient depth to put the track and support behind there without hitting the roof, right?   You'll also need enough space to get around the track structure back in there, looks like a tight squeeze.

Maybe a TV camera and lighting to keep an eye on trains in the tunnel.   Another cool idea is hidden yard space...

John,  There is enough room to work... not much, but enough.  I took a 16" x 9" piece of ply in there and laid the 16" side on the studs.  I could get my head and hands above the plane to work... not fun, but doable (with a little swearing).  I'm liking the camera!!!!  THANKS!!!

Don't sweat the Atlas track.  That stuff is very stable, much more so than the GG most of us use.  Just make sure that you do not over tighten the track ends and cause dips.

Henning's Trains has had the same Atlas track outside the store summer/winter for about ten years, still works fine.   The stuff is bulletproof, just consider Ross switches with it.

@Dennis-LaRock posted:

Mark,  Good point!   I'm still in somewhat decent shape (too fat though).  I think I should be good for a while and my son is only a few blocks away.   I have been thinking about soldering the rails and I don't run my trains very fast.  If I have to go in there two or three times a year it should be fine... if I have to go in once a month ...that could be an issue.

We live in the house my wife’s grandma lived in.  She used to send our younger daughter into the attic to get things.  Since both daughters live within 2 miles of us, I have told her I may need to enlist her agility again.  😄

You are looking at creating a 21 foot long tunnel with limited access and different environmental conditions from the rest of the room and layout.  I would not do it.

I'm all in on the Atlas switches.  I got a very, *very* good deal on them... all are brand new and I have three extra (16 total).  I'll see how they perform and hold up over time.  I'm coming off Super-O so it's a big change for me.

Sorry, why do they call it a "Knee Wall? Never heard of such a thing. Don

I'm now thinking that I will not plug the Portals when not in use.  It was a tad warm this summer and the A/C never came on... not once.  The heat pump is so efficient and that space is so small that I doubt the differences between the spaces would be detrimental to the performance.

@scale rail posted:

Sorry, why do they call it a "Knee Wall? Never heard of such a thing. Don

Kwiki from Wiki... A knee wall is a short wall, typically under three feet (one metre) in height, used to support the rafters in timber roof construction. In his book A Visual Dictionary of Architecture, Francis D. K. Ching defines a knee wall as "a short wall supporting rafters at some intermediate position along their length."^[1] The knee wall provides support to rafters which therefore need not be large enough to span from the ridge to the eaves.

My Knee Wall is 46" high...

I have an attic room layout, with hip walls like yours. I decided on an around the room layout, as the train table and tracks near the walls has a low ceiling and you cannot stand there anyway.  I did not, nor would I, punch a hole into the attic space. Besides the temperature imbalance, The lack of access will become a growing problem, only getting worse with time. When access is an issue, you may find you don't want to run trains on "those" tracks.

The around the room layout also made it easy to reach all the tracks, as the table only needed to be about 24" to 30" deep, depending on the location. I have one location that has a hinged section to gain easy access into the middle of the layout from the room entrance. Lots of room for guests to visit in comfort and watch the trains.   

Your room looks quite large. Don't know what the area looks like from the pictures. You may have already gone through all the options, as you considered 15 options. Going into the attic space can be complex, and trains love to derail at the most inconvenient locations.

Good Luck:

Joe,

The attic is a fully functional apartment... bathroom, kitchen, bedroom etc.  It serves as our office, guest quarters and my wife's hobby space as well.  I would have loved to have the entire space for my trains but I love my wife more and compromise isn't all that terrible.  I greatly appreciate the space that I have.

Dennis, thanks for the info. My good friend had something like your talking about but you could see the trains. Even than it was a pain. He seldom used that back line because something always happened back there even though there were no switches. Think about it. Do you really need the outside line? Don

Don,

Wow!  Steeper pitch than mine!  With my Super-O I almost never had a derailment on curves/straights... and when I did ...it was because I was horsing around i.e., running the MPC Chessie at 20 volts until Gomez'd.  I don't drink anymore (well... maybe a little) and that should help.  So with O72 and 40" rigid *soldered* together through the entirety of the tunnel it should hold straight, level and true with great continuity.  It wouldn't be the first time I've been mistaken.  As a business person I made some mistakes fortunately the better part of the decisions I made were correct.  I guess it's just in my nature to push the limits.

Here's an off-the-wall suggestion. Consider using 5 rail stainless steel GarGraves behind the knee wall. I use the 5 rail track on bridges. It is virtually impossible to derail. On my attic layout, the SS GarGraves passes from a conditioned to an unconditioned area of out attic. ZERO signs of corrosion since 2010.

Tom,

That's interesting.  I don't think I can solder it though... weld yes ...but not solder?

Yeah, you won't be soldering the joints. But FWIW, I haven't seen the need to.

Dennis, Gomez'd the train. Great reference.

I think you can build it, and if for some reason it becomes a problem, you can just abandon it until you can figure out the problem.  Put a switch in line with the track power to that section and just shut it off if you have issues until you get it fixed.  It is effect what I do with model engines and the prototype does with engines and cars that have issues.  Take them out of service until they can be fixed.

Dennis

I used Gargraves trackage, built 2 sections outside the knee wall, built and attached the brackets inside an then brought them in, they were also pre wired so installation and leveling was pretty easy as long as you don't mind a few head bangs. A hard hat would help.  I do recommend signal lights so you know if anything is there, every once in a while I do forget, not pretty. All in all I'm very happy with this set up and would do it again. I have one door on each side, I go through the walls on both sides of the room and have a creeper seat to be able to scoot down the track without having to crawl. The room is heated and air conditioned and never had a problem with that or moisture while living in New England.  It is also a great storage area for all those boxes etc. Just be sure the entrance is high enough for when you pick up a higher than normal car carrier etc.

BTW the car cleaned up just fine

Lots of good ideas presented here. Here are some of my ideas.

You do not want to go back there after you install the track. Use long sections of track to minimize joints. Do not solder the rails together. Leave room for the rails to expand ans contract. Put feeder wires on each track before you install the track in the knee wall. Connect as many as needed. Insulate the unused ones and fasten them out of the way. Electrically isolate (the center rail) the section of track for easy trouble shooting. When that short appear on the layout, you just turn the knee wall off to simplify trouble shooting.

Guards or shields are good to keep trains from falling as mentioned above.

Something to remember, its not just drywall, theres framing behind it. When you near the end of an O72 U-turn, it gets pretty long and flat. You need to make sure that your studs line up with the track in a favorable fashion. I punched through the wall under my basement stair landing. I was able to aim where and how it came through. Since you already have everything in place, you're basically going to deal with whatever you get on the other side of that drywall. This track is 2 sections of 36"R Atlas that converts to flex inside the hole and as you can see, it takes an entire stud bay to pass the track through and miss the stud. My clearance car was a 68' bulkhead flat car. I didn't bother with anything longer, as I dont plan on really even running cars as long as that.

Homes like this were originally design as single story. The access to the second level/added dormers/rooms was later.  Often the ceiling joints were limited as flooring joist. Example: Ceiling joint 2" X 6", Floor joist 2" X 8" (10" better). Note that dimensional lumber is also related to the length of span.    The Knee walls may also be part of an effort to support relatively light ceiling joists, that  have become floor support. IMO. Pictures above show some interesting framing lumber bottom of the knee wall.   

@Gilly@N&W posted:

Here's an off-the-wall suggestion. Consider using 5 rail stainless steel GarGraves behind the knee wall. I use the 5 rail track on bridges. It is virtually impossible to derail. On my attic layout, the SS GarGraves passes from a conditioned to an unconditioned area of out attic. ZERO signs of corrosion since 2010.

Inquiring minds want to know.  WHY is it almost impossible to derail on the 5-rail track?  I have some here, and it doesn't look any harder to derail than on any other track, so I have to ask.

I don't see any issues doing this, and I sure wouldn't abandon the O72 loop, you may be really happy you allowed for it.   I like the idea of prefab for the track and support, and also I'd simply put some guard rails on either side to contain any derailment.  I wouldn't solder it, I'd also go with the drops on every length and just bus those together.  Obviously, lights are a must, and I'd seriously consider a little TV setup so I could see what was happening back there.  Signals to let you know something is parked back there aren't a bad idea either.

That video access is a good tip.  Having several hidden tracks I sometime cannot find a train,  for a while!

@sidehack posted:

Dennis

I used Gargraves trackage, built 2 sections outside the knee wall, built and attached the brackets inside an then brought them in, they were also pre wired so installation and leveling was pretty easy as long as you don't mind a few head bangs. A hard hat would help.  I do recommend signal lights so you know if anything is there, every once in a while I do forget, not pretty. All in all I'm very happy with this set up and would do it again. I have one door on each side, I go through the walls on both sides of the room and have a creeper seat to be able to scoot down the track without having to crawl. The room is heated and air conditioned and never had a problem with that or moisture while living in New England.  It is also a great storage area for all those boxes etc. Just be sure the entrance is high enough for when you pick up a higher than normal car carrier etc.

BTW the car cleaned up just fine

OH! So... here's the guy who planted the seed!

Ray... THANK YOU!!!!  You *ARE* the MAN!  Great photos and detail (as always).   Your pitch looks to be similar to mine @ 6/12 (that's about 28 degrees).   All I want for Christmas is a creeper seat!

I'll probably have to do 3 sections as it's going to be approximately 18' from entry to exit.  If, I have to take out a stud or two that's fine... I have some very heavy steel lintels (angle iron) that can easily carry the load so I won't have to build headers and I won't lose any clearance.

Thanks again Ray!

@gunrunnerjohn posted:

Inquiring minds want to know.  WHY is it almost impossible to derail on the 5-rail track?  I have some here, and it doesn't look any harder to derail than on any other track, so I have to ask.

I don't see any issues doing this, and I sure wouldn't abandon the O72 loop, you may be really happy you allowed for it.   I like the idea of prefab for the track and support, and also I'd simply put some guard rails on either side to contain any derailment.  I wouldn't solder it, I'd also go with the drops on every length and just bus those together.  Obviously, lights are a must, and I'd seriously consider a little TV setup so I could see what was happening back there.  Signals to let you know something is parked back there aren't a bad idea either.

Ditto on the Five Rail... I'd like to know as well.

All great suggestions!  The TV Camera and Signals are a must... as well as lighting.  There are two outlets on that wall very close to the entry and exit points.  Darn!!! Should I wrap it in a cowl and make it look like the Lincoln Tunnel?  Stop dennis Stop!

Thanks John!!!

@Boilermaker1 posted:

Something to remember, its not just drywall, theres framing behind it. When you near the end of an O72 U-turn, it gets pretty long and flat. You need to make sure that your studs line up with the track in a favorable fashion. I punched through the wall under my basement stair landing. I was able to aim where and how it came through. Since you already have everything in place, you're basically going to deal with whatever you get on the other side of that drywall. This track is 2 sections of 36"R Atlas that converts to flex inside the hole and as you can see, it takes an entire stud bay to pass the track through and miss the stud. My clearance car was a 68' bulkhead flat car. I didn't bother with anything longer, as I dont plan on really even running cars as long as that.

Good point... and, Nice Photo!  I'm assuming that I will have to remove 1 stud on each end.   When I put in the new air handler for the heat pump I removed a stud and put in a heavy steel Lentil then placed Jack Studs under the Lentil to support it.

THANK YOU!!!!

@Mike CT posted:

Homes like this were originally design as single story. The access to the second level/added dormers/rooms was later.  Often the ceiling joints were limited as flooring joist. Example: Ceiling joint 2" X 6", Floor joist 2" X 8" (10" better). Note that dimensional lumber is also related to the length of span.    The Knee walls may also be part of an effort to support relatively light ceiling joists, that  have become floor support. IMO. Pictures above show some interesting framing lumber bottom of the knee wall.   

Yup, my house was built in 1905...  12' ceilings.  The roof is slate, the rafters are rough sawed at a full 2 x 8.  The ceiling joists are rough sawed at a full 2 x 12.   The knee wall was installed at a much later date... it's all modern kiln dried dimensional lumber.  Whoever turned the attic into an apartment probably added the knee wall so there was some end point to the slope...

Here's the Iron Work I did to get to the 'Train Room' (O96 spiral w inner handrail)

Carried each layout section up these by myself... 25 steps

This is where I sit when I talk to Ray on the phone...

I have a attic layout and never thought about till now but if I was going to extend  it..

I  would go behind and add new 2x4 and then make a shelf and leave the original  layout table where it is but just extend it  remove just the sections   and have new drywall , and those new supports so I could have my layout widened