Are 2 Sheets Of 19mm MDF Enough Mass For A Door?

[shomium]

I'm planning to make a door out of 2 sheets of MDF (and a double layer of sealing rubber at edges).
Initially I wanted to put a Sheetblok in between them, but when I saw a price (500eur for 3,7m2 of Sheetblok at croatian dealer), was immediately discouraged.

Q1.)
Regarding the mass: are 2 sheets of 19mm MDF enough?

Q2.)
Regarding a Sheetblok surrogate idea: would a sheet of semi rigid (industrial seal purpose) rubber do the job of spring in MSM?

[Soundman2020]

Regarding the mass: are 2 sheets of 19mm MDF enough?

Enough for what? You didn't give enough information for anyone to give you a clear answer.

Lots of questions: How much isolation do you need? Is this MSM construction? What is the construction of the rest of the room like, and specifically, what are the surface densities of each of your two leaves? How much air gap will there be between your two doors?

- Stuart -

[shomium]

Stuart,

Room details are in my design thread (sorry for not providing link earlier).

As of yet I didn't took any tests with a SPL meter nor made any measurements with REW type of software because of lack of the doors.
So, for now, my plan is to make a door (single door) out of 2 MDF boards, maybe sandwiching a rubber (unless someone here with an experience says it is a silly idea). Anyway, there would be left enough space for beefing them up or even making a double door after taking tests and measurements..

And to reformulate my question: how much STC can I expect from such construction?

[xSpace]

The problem you are going to get into is this. If you do not build this door, the MDF door, much like a cabinet door with an outside perimeter piece of actual wood glued and screwed the potential for this door, or rather the screws you insert into the mdf panels, to walk right off the five knuckle hinges you will be using is imminent.

[shomium]

xSpace,

I'm having difficulties comprehending your message. Here is what I had in mind:

• Solid-wood door frame;
  2 MDF boards glued and screwed togheter (I orderd 25mm thick MDF panel);
  Seals all around both of MDF boards edges (purple colored in skp file);
  3x massive one-knuckle hinge (as in attachment)

Q1.) How much STC would that give?
Q2.) Should I throw in a rubber sheet (which I have in disposal) in between MDF boards or don't need to bother with it?

[Ro]

Howdy,

Your picture solves a few unanswered questions. Like X was talking regular hinges with screws on the perimeter of the MDF. your drawing shows other hinges which solves THAT problem. Have you seen MY door-design? That design is constructed like X-space talks about. Here's the link: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=12664

The thickness (or better: MASS) of your door should -at least- be equal to your wall where the door will be placed in. If you have, for example, two sheets of 15mm Gypsum for your walls. The two MDF sheets of 19mm will be sufficient. MDF has about the same density (read, mass) as gypsum.

On the other hand. If you have three sheets of 15mm Gypsum you'll have 45mm of thickness. Two sheets of 19mm MDF will be 36mm in total. That's 9mm less. (remember in this case you can replace the word 'thickness' for 'mass'). you should, at a minimum, add another layer of 9mm MDF in that case.

Seal it correctly and you're save.

btw. This topic is in the subforum "acoustics", why? I'd say put this in the DESIGN sub.