Solid Core Doors

Origin Productions · Post by **Origin Productions** » Sat Apr 03, 2004 2:51 pm

I have a solid core door that has a round hole drilled through to accommodate a door knob/lock assembly. I was advised that solid core doors should not have holes in them, and that I should use door handles in combination with industrial door closers. Is there a method of sealing up those holes (possibly with fiber glass)? Will there be more potential for sound bleed if I use a patched up door?

If you like you can see an updated layout of the studio design on my website. www.originproductions.ca Go to new location info. My main concern is the double door that goes from the live room into the vox booth.

Thanks
James

knightfly · Post by **knightfly** » Sat Apr 03, 2004 4:43 pm

Fixall patching compound (green box, Home Depot or similar) has a pretty dense composition - you could remove the door, lay it flat on a table, put a piece of waxed paper under the hole, and fill the hole in layers (no more than about 1/4" at a time) letting it dry between layers. fill it flush with the top, then put a pair of those stainless or brass "push plates" over it. Should end up at least as good as the rest of the door... Steve

AndrewMc · Post by **AndrewMc** » Tue Apr 06, 2004 6:02 am

I bought 4 solid core doors and they all had the holes for the handles pre-drilled. You really cannot get around needing the hole for the handle assembly.

Industrial door handles are heavy duty (& much more expensive) - they typically need a bigger hole than the standard handle, so from a studio perspective I cannot see much upside in using them.

On two of my doors I attached 3/4" MDF to the door overlapping the door on all sides except the hinge side. The MDF fits flush to the wall when the door is closed due to the thickness of drywall around the door frame. Then added a seal where the MDF hits the frame. For the handle I used a router to router down the MDF just deep enough that the handle would fit & then only drilled through the necessary holes for the door mechanism spindle & screws to fit through.

The doors are tanks. When they close it sounds like one of those airlocks closing on star trek. They kill the sound as well - which is the important point.

knightfly · Post by **knightfly** » Tue Apr 06, 2004 6:54 am

Eliminating the hole and replacing it with solid material helps cut down on transmission, but you need a way to keep the door closed. If using compression seals with a closer, or magnetic seals, you only need a push plate on the side the door swings AWAY from - on the pull side, one of those Stanley Barn door handles with screws about 1/4" shorter than total door thickness would work for a pull - the nicer stainless ones with built in backing plate are more expensive but nicer looking. I know you get some flanking with screws nearly all the way through, but it's nowhere near as bad as a hole all the way through that's 2-3 inches in diameter... Steve

AndrewMc · Post by **AndrewMc** » Tue Apr 06, 2004 8:07 am

knightfly wrote:Eliminating the hole and replacing it with solid material helps cut down on transmission, but you need a way to keep the door closed. If using compression seals with a closer, or magnetic seals, you only need a push plate on the side the door swings AWAY from - on the pull side, one of those Stanley Barn door handles with screws about 1/4" shorter than total door thickness would work for a pull - the nicer stainless ones with built in backing plate are more expensive but nicer looking. I know you get some flanking with screws nearly all the way through, but it's nowhere near as bad as a hole all the way through that's 2-3 inches in diameter... Steve

Sounds like a lot of work for hardly any benefit - just my 2cents

knightfly · Post by **knightfly** » Wed Apr 07, 2004 12:09 am

Not really - if a 1/64" crack 3-4 feet long can lose 6-9 dB of TL, it doesn't seem like a good idea to leave a big hole if you have a choice... Steve

AndrewMc · Post by **AndrewMc** » Wed Apr 07, 2004 1:29 am

The hole is covered by a door handle assembly. The main point is that a door is a weak spot anyway - so if you are planning to stop a lot of sound with just one door then it's not going to work. Normally the door would lead to another door or a soundlock room.

The door handle also is important for pulling the door closed tight and holding it there against the door seals. If you fill the hole and then rely on some kind of magnetic seal with a pull handle on the door you are going to end up with a crap door vs the minimal difference a door handle adds to a door that is already a weak spot.

knightfly · Post by **knightfly** » Wed Apr 07, 2004 8:52 am

If you're talking about normal, house-type door knobs they have about as much useful sound isolation as a piece of saran wrap. Just a thin metal cap over a hole that's only about 60% filled with sound conducting metal rods, etc - That's why I recommended filling the hole in the door. I'm not sure why using magnetic seals automatically results in a "crap door" - what they SHOULD accomplish is the elimination of the NEED for a latch, most of which DO penetrate the door. With either mag seals or a closer, you still need a way to pull the door open but NOT to close it.

If you use a closer, then magnetic seals aren't needed (just good compression seals) - the closer (or mag seals) is used to keep from having to penetrate the door at all, and since ANY break in the mass causes disproportionate loss in performance that's why I recommended against it.

I agree that the ONLY way to get GOOD isolation is with double doors - the physics are no different tnan with good wall construction, other than the seal problem. I also agree that two "crap doors" in tandem beats ONE "crap door", but two GOOD doors beats 'em all -

We getting closer to agreement, or should we both just drop it and agree to disagree? Steve

cfuehrer · Post by **cfuehrer** » Wed Apr 07, 2004 10:55 am

OK, I'm confused about your message Steve.

I am trying to find doors for my place and could use the advise. So I should not go for normal lever handles? I should plug the hole and mount the big U shaped handles?

I have been looking at the Schlage commerical levers like this one.

Post by **Aaronw** » Wed Apr 07, 2004 11:53 pm

Carl,

Is it necessary or required to have locks on the control room doors?

Maybe use something like a hospital door latch?

They do make doors without the holes drilled. I picked up 2 solid core doors at Home Depot here awhile back that are not drilled yet. Mostly because I wasn't sure if I was going to put handles on or not. If I do, it'll probably be only for a deadbolt and use pull handles and push plates for the doors. I'm definately using a closer, I just need to figure out what type of seals to use, so I could use some advise here as well. Not to mention the kick plate and seals (affordable).

Aaron

cfuehrer · Post by **cfuehrer** » Thu Apr 08, 2004 5:47 am

the doors into my control room, stoage room and vocal booth will have locks. I need to secure rooms due to certain clientel I have.

Eggman · Post by **Eggman** » Thu Apr 08, 2004 5:56 am

Excuse me for jumping in here.......I too could use some info, diagrams, sources, recommendations, etc on magnetic door seals.

As usual, thanks for your time and input.
Doug

mcguin · Post by **mcguin** » Thu Apr 08, 2004 8:59 am

hi there
just bought all of my door seals - can't beat the price or service - Steve at Zero International.
zerointernational.com

dan

cfuehrer · Post by **cfuehrer** » Thu Apr 08, 2004 9:16 am

I am going with the #485-2 seals from here: http://www.acousticalsolutions.com/prod ... l_kits.asp

So far I a getting 1.75" doors. I might also get the Cam Lift hinges: http://www.acousticalsolutions.com/prod ... hinges.asp

knightfly · Post by **knightfly** » Thu Apr 08, 2004 9:38 am

Guise, I went to Overly's site yesterday to look around, and their doors have what looks exactly like Carl's handle sticking out of them - I'm confused here myself now, wondering how they keep from compromising the integrity of the door mass.

Anybody think to ask some of the other vendors mentioned how/why they use what they use for door handles, and why they allow penetrations?

I'm so buried these days I'm not sure when I'll get time to pursue this. What little time I can steal is never during business hours, so if it's not on the web I'm sorta screwed... Steve