@Boeingman

1/2” thick is plenty for layout decking. Especially if you’re going to put a 1/2” thick Homasote sheet over it for sound suppression. IMO, 3/4” thick plywood is too thick, heavy, and cumbersome. Just my 2 cents.

Thank you. That’s what I was thinking.

I started with 3/4 inch particle board as that was all I could get when overseas.  It is very heavy for my portable layout.  When back in the USA I used 1/2 inch cheap plywood and it was much lighter and plenty strong as I had my layout on the floor and walked on it when setting up each winter.

My problem was the sound as the 1/2 inch plywood was much nosier than the 3/4 inch particle board as I did not use Homasote on either board.  I quieted the 1/2 inch board down by installing small pieces of truck inner tube under each rail tie that made it quieter.

Charlie

I used a 1/2" 4 x 8 Underlayment grade plywood in fir (more stable than southern yellow pine especially in basements or other high humidity areas)...a little more expensive than CDX, but this product has less voids and a plugged and touch sanded face veneer.  If you install it 24" on center there should be no problem with structural integrity.  Using a 3/4 plywood product is unnecessary...it's heavy to work with and you'll save some money by using a 1/2" product.  If you plan to go over the 1/2" plywood with a sound deadening product, then 1/2 CDX in fir should do the job.  Good luck...

1/2" plywood is plenty, and less-expensive OSB or CDX can be used if you're covering it.  3/4" is overkill and an unnecessary expense.  Most layouts are overbuilt - 1x4 framing and 2x2 legs are sufficient for most situations.  (Can even frame with 1x3 or 1x2 if available at a reasonable cost, but I wouldn't waste 1x4 by ripping it.)

This discussion always takes on an almost religious fervor.  In addition, the use of foam, homasote, cork, or nothing as underlayment is hotly debated and a matter of personal choice.  If you search the forum for "plywood" and "homasote", you'll find LOTS of opinions. 

I went deluxe, 1/2" Baltic Birch and 1/2" Homasote.  It's rock solid.

Depends on your bench work  mine was 16" on center 2x4  made a stong base

I used 3/8 plywood smooth on one side rough on the other

What I liked about it was I can use a hand drill bit when it was time to add wiring you can stand on mine and look at my post from when I started this site.. Good luck and enjoy the journey.daniel

here is the titled

                                 Daniel's Attic Layout has begun...

not sure how to make the link but if you copy and paste in the search you'll find it..

@Boeingman...

I used 1/2" OSB (was cheaper than plywood but is a bit heavier) on 1x4 beams on top of 1x4 "L" girders. The OSB was covered with homasote.

I crawl all over the layout and it's solid.

My old layout was all 1/2" plywood and it was plenty sturdy for me to crawl around on. That being said, I'm super happy I went with 3/4" A/C on my new layout. I can practically dance on the deck and not worry about it failing.

- Jason

3/4 inch MDF no homosote or foam. Economical and quiet. I only hear the clickety clack!

I went with 3/4” for the main level and the upper shelf layout. For my smaller lower level I did 1/2”. I prefer the 3/4” because I can use longer screws to attach lighting (for under the cabinets) and cable stays.

No to hijack the thread, but is it necessary/desirable to paint the plywood on both sides ?

Thks,

Rich in SD

@jdstucks posted:

My old layout was all 1/2" plywood and it was plenty sturdy for me to crawl around on. That being said, I'm super happy I went with 3/4" A/C on my new layout. I can practically dance on the deck and not worry about it failing.

- Jason

With or without mirror ball ? Inquiring minds want to know !

I used 3/4 plywood on my old Standard Gauge layout.  I figured with the weight of the engines (they are heavy), it would be necessary.  Overkill in my opinion.  Also, I have no desire nor reason to stand on my layout.

@trestleking posted:

No to hijack the thread, but is it necessary/desirable to paint the plywood on both sides ?

Thks,

Rich in SD

This is a total SWAG but.....may be if you have high humidity in your location painting both sides might help (my Yoda must be showing)?

I used 1/2 inch plywood over 2x4 framing 20 Inches on Center,layout is 21x 20 and no problem walking on it during track laying.Used woodland Scenics foam road bed and it is very quiet.

Mikey

Thank you all for your inputs. Talking to my friend who sells wood products I’ve decided to go with 1/2” Baltic Birch he can sell me at a very reasonable price. From there I’ll go with Homasote 440 he has. 1/2”. That gives me plenty to screw into and the sound deadening I need for this large garage area. 13X35X 15 high ceilings. Lots of echo now, so sound proofing I need. My Benchwork was designed and built by Mianne Benchworks. I’m extremely happy with his product and quality of materials. Building it is time consuming, but the results are proving well worth the time. Thanks again for this forum and everyone who has helped me start this life long dream.

1/2 inch B/C grade plywood is more than enough, assuming supports are no more than 16" on center.   Screw it down and don't be shy about using too many screws.

Don't go with CDX, it is really poor cheap stuff.  Lots of knot holes in the bottom (the grade "D" side).  When used in roofing, it sags in the middle, creating numerous dark "valleys" running down the roofs.  This is true of OSB as well.

Don't go cheap on your plywood sheathing.   The extra money is definitely worth it.

Mannyrock

"
D

Trestleking,

Instead of trying to buy Baltic Birch plywood, I buy regular high-quality B/C plywood and simply give it a quick thick paint job of Kilz II primer on both sides, and on all edges.  It NEVER warps after that.   You have to keep the plywood laying flat in a cool dry place, and fully weighted down with lumber or other weights,  to keep it from curling until you can paint it.  I generally try to paint within 48 hours after buying the plywood.  Do not let the unpainted sheets be exposed to direct sunlight , or they will curl up at the edges in a matter of 2 to 3 hours.

I am sure that the Baltic Birch is superior stuff, but it only takes about 2 hours of painting and drying time to paint the regular plywood and it saved me from a lot of driving time, expense and headaches trying to find the Birch.

Mannyrock

Hey Captain Boeingman, I think your selection in wood is wise and that you are off to a great start.

BTW, is that a 737 cockpit you're sittin' in? 🤔

I used 1/2 inch on mine.   I can't remember CDX or something else.   Cost was a very big deal at the time.    I  am not totally happy with that.   The layout is 30 years old however.    My layout is 23x47 feet and is walk-in - ie around the walls and a large peninsula.    I can get up on the layout if need be strength is not a problem. 

The problem I have is that some sections have warped or curled creating dips and bumps.   I did support it on 16 inch centers but it still curled.   

I think 3/4 inch is more stable and won't tend to this as much.  

@Mannyrock posted:

give it a quick thick paint job of Kilz II primer on both sides, and on all edges.  It NEVER warps after that.   

Mannyrock

It doesn't warp while waiting for 1 side to dry?

I built using 3/4 inch ply on MIANNE benchwork layered with 1/4 inch cork and acoustic ceiling tile on top.

Quiet.  Strong,  Durable.

@jdstucks posted:

My old layout was all 1/2" plywood and it was plenty sturdy for me to crawl around on. That being said, I'm super happy I went with 3/4" A/C on my new layout. I can practically dance on the deck and not worry about it failing.

- Jason

@Junior posted:

With or without mirror ball ? Inquiring minds want to know !

Jerry

@baltimoretrainworks posted:

Jerry

Hysterical Jerry...I love it!

1/2 Thick 4 ft by 8 ft sheets supported on transverse  L shape girders, these L shape girders bear on L shape longitudinal rails. The plywood sheet, transverse L shape girders and L shape longitudinal side rails make the table top. Legs are 2 inch by 2 inch length 40 inches. All L shape are wood glued and screwed together, plywood finished top, bottom course all wood is pine. Buy a good grade of lumber that is straight and  seasoned to prevent twisting minimize knots. I purchased most of my wood from a lumber yard, I selected  the lumber with the lumber yard employees.   

Apply 3 or 4 transverse L shape girders to the L shape longitudinal side rails, then the L shape  longitudinal side rails to the 4 corner legs. Once the table(s) are built add 45 degree bracing legs to L shaped girders. Attach(screw) the plywood sheet to the transverse L shape girders and start laying track. If under table switch motors (Tortouse) are used, mount to the switches and apply the switch motors, additional transverse L shaped girders can now be added. My L shape girders are  made using 1 by 2 and 1 by 4 rectangular lumber. Centers of transverse L shape girders 18 to 20 inch. 

@Yellowstone Special posted:

Hey Captain Boeingman, I think your selection in wood is wise and that you are off to a great start.

BTW, is that a 737 cockpit you're sittin' in? 🤔

Yes 737. I’m now on 777

Pittsburgh area.  Model train group, Fort Pitt High Railers, use 1/4" luan board, for the modules, and 1" X 4" cross members, to reduce weight.

Most annoying problem:   The tips, of track screws, can be exposed, on the bottom of the module.  Screw tips were removed with a dremel/cutting tool.

I used 5/8" plywood on my old layout. (Since 1/2" plywood is no longer actually a half inch thick.) With 1/2" homasote on top, it was very sturdy. My friends said you could walk on it. I said you could park a car on it.

@gunrunnerjohn posted:

I went deluxe, 1/2" Baltic Birch and 1/2" Homasote.  It's rock solid.

Question: Did you paint your birch plywood and homasote?

I think it's important to note that not all plywood is created equally.  There is some 1/2" stuff that is complete junk.  1/2" Baltic Birch should be a nice surface though.

Also if your stacking 1/2" Homasote on top of 1/2" plywood your table is certainly comparable to the rigidity of the 3/4" plywood that many like myself have installed.

I don't like Homasote or the associated mess it creates.  Very happy with the 3/4" A/C plywood along with foam and cork roadbed used for my railroad.

@Boeingman posted:

Question: Did you paint your birch plywood and homasote?

I painted the Homasote after it was on.  We had minimal mess from the Homasote, it all hinges on handling the construction properly.

IME you don't need 3/4", that is overkill. I used 3/8 on a grid frame with 16" centers. The layout is U shaped and the plywood is held down on all sides because of the way I made it (it is a box grid, so the edges of the rectangular "box" also hold the plywood), and it has not warped, and has been strong enough when I had to go on top of it and I am not a lightweight.

I agree with buying better quality plywood, baltic birch is nice but good quality floor underlayment is fine as well. I also recommend going with a lumber yard, just too much bad luck with big box wood.

@gunrunnerjohn posted:

I painted the Homasote after it was on.  We had minimal mess from the Homasote, it all hinges on handling the construction properly.

I too, used 1/2" plywood and 1/2" Homasote and painted the Homasote after it was on. I found it less messy to work with than styrofoam would have been and easier as well.

If you do straight cuts of the Homasote with a sharp utility knife, and any curves with a vacuum at the ready, there is minimal mess using the Homasote.  I had very little cleanup after the Homasote was on.

Straight cuts were with a utility knife.

Cutting with a vacuum close at hand.

Routing the edges with a vacuum close at hand.

Is the dancer grooving to Soul Train or Locomotion ?

🚂

@CBQ_Bill posted:

Is the dancer grooving to Soul Train or Locomotion ?

🚂

Ha ha ha ha! 😂😂😂😂

@CBQ_Bill posted:

Is the dancer grooving to Soul Train or Locomotion ?

🚂

Well played @CBQ_Bill.....well played....

@gunrunnerjohn posted:

If you do straight cuts of the Homasote with a sharp utility knife, and any curves with a vacuum at the ready, there is minimal mess using the Homasote.  I had very little cleanup after the Homasote was on.

Straight cuts were with a utility knife.

Cutting with a vacuum close at hand.

Routing the edges with a vacuum close at hand.

So homasote can be routered? Can it be precut on a table saw prior to placement? Thx