Rubber pucks - roughly how many do I need?

Johnrg · Post by **Johnrg** » Tue Apr 19, 2005 8:38 am

I need to order some 60durometer rubber pucks to float my new tracking room floor. .

I did a search and found 12mm (1/2") and 25mm (1") mentioned. What one is it?

The floor area will be about 14m2. Can anyone give me some idea approx. how many I actually need. (see plan attached)

Also the existing floor has carpet installed, I am going to lay the new floor straight over the carpet rather than ripping it up - seems like a good idea as the carpet will add as insulation to the existing floor and help even out the pucks.

Any really serious reason not to do this (room is nice and dry and suspended above the ground so there no chance of rot)

Thanks

JohnG

knightfly · Post by **knightfly** » Tue Apr 19, 2005 1:04 pm

I need to order some 60durometer rubber pucks to float my new tracking room floor. I did a search and found 12mm (1/2") and 25mm (1") mentioned. What one is it?

Thicker the better; I'd use the 1" ones.

The floor area will be about 14m2. Can anyone give me some idea approx. how many I actually need. (see plan attached)

Depends on a LOT of things; construction of EVERYTHING that's floated on the pucks, including any walls, heavy equipment, etc -

Also the existing floor has carpet installed, I am going to lay the new floor straight over the carpet rather than ripping it up - seems like a good idea as the carpet will add as insulation to the existing floor and help even out the pucks.

No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No also Nyet, Nine, Nicht, etc... Carpet is a great place to grow mold, mites, fungus, etc - sandwiching it between two solid layers will GUARANTEE a good crop. (Did I mention this wasn't a good idea??!? :=))

Any really serious reason not to do this (room is nice and dry and suspended above the ground so there no chance of rot)

Your term "suspended above the ground" raises yet another red flag - I just re-read your other thread to see what was mentioned. Can you post the EXACT construction of your existing floor - spacing of joists, longest un-supported span of joists, etc? Also, didn't see what MATERIAL you intend to use for the floated floor; wood, concrete, ?? - the more details you post, the sooner I can help you figure out if it's a "go" or not... Steve

Johnrg · Post by **Johnrg** » Tue Apr 19, 2005 3:07 pm

Hi Steve.

The floors exact construction is as follows:

concrete housing piles 200mm diameter concreated into the ground at approx. 1.5m intervals
150x50mm beams bolted to these, one foot of the ground
100x50mm joists on top of the 150x50 beams, ruuning the other direction at 600mm centers
building paper
20mm chipboard flooring
carpet underlay
carpet.

My builder and an architect have inspected the construction and both said it can easiliy hold the weight of the new "room inside a room" I am making.

This suspended floor, as I mentioned in my other post, is firm to walk on but slightly bouncy/boomy to jump heavily up and down on. This was my reason to float a new floor/walls etc. (rightly or wrongly).

The new floated floor will be the traditional - rubber puck - 2x4 on the side - insulation in cavities and 2x20mm chipboard glued and screwed on the top. (inside out walls and ceiling mounted on this floor) - basically SAE room plan.

awaiting your reply.

Thanks for your help - the carpets comming up!!!!

JohnG

knightfly · Post by **knightfly** » Tue Apr 19, 2005 7:50 pm

With those floor specs, your floor will just about keep up with your walls - ceilings, not sure yet. You will want to re-read ALL the threads on floating floors; two good ones to start are Aaron's and Sharward's threads.

In your case, you'll be floating over a framed floor, so the pucks MUST be centered over joists; even better if they're centered over the concrete pillars. Problem is, 2x lumber laid flat won't span a meter and a half very well, so you'll probably have to put pucks halfway between as well.

The SIZE of the pucks will depend on your total floated weight, and the spacing between the pucks - you will need to do a bit of homework there, Sharward's thread will probably be some help. You want the pucks to compress by roughly 10% for longest life with decent isolation; if you don't care about lifetime, more compression (around 25%) will improve isolation but at a much reduced lifetime (don't ask me how much reduced, don't know exactly)

If you get this part wrong, you will be wasting your time completely - as is, your floor will have its resonant point somewhere around 78 hZ, with its worst performance at least an octave either side of that frequency. To get away from that, you'd need to use 6x2's on edge and about 100mm concrete floated on top; not an option here... Steve

Johnrg · Post by **Johnrg** » Wed Apr 20, 2005 7:01 am

Thanks Steve,

The ceiling is a tricky one for sure. I

f I installed a RC to the existing ceiling and filled this narrow cavity with insulation then added a new layer (or two) of wallboard how sucessful would this be from decoupling the new and existing ceiling as a compromise between ceiling height and isolation?

To answer your question the total weight of all materials including timber, wallboard and insulation + one person and drums will be on/off this floated floor will be 1200kg (2645pounds).

Understand the point about placing the pucks over the existing joists - no problem there.

AVare · Post by **AVare** » Wed Apr 20, 2005 9:02 am

f I installed a RC to the existing ceiling and filled this narrow cavity with insulation then added a new layer (or two) of wallboard how sucessful would this be from decoupling the new and existing ceiling as a compromise between ceiling height and isolation?

You will make the LF TL worse witht he triple leaf.

Andre

Johnrg · Post by **Johnrg** » Wed Apr 20, 2005 10:11 am

Hi there Andre,

I don't think that it will be triple leaf as the roof/attic cavity above the 13mm wallboard has a large airgap and then roofing iron (not acoustically sealed). If I disregard this then the ceiling will be:

13mm wall board attached to roof trusses - mass

RC attached to 13mm wallboard - (small airgap with insulation) - air

15mm wallboard attached to RC - mass. (I could increase this to two wallboards to increase the mass).

Basically my idea is that the RC will de-couple the new 15mm wallboard from the existing 13mm wallboard that both the control room and tracking room currently share.

I know its not ideal but maybe a compromise between isolation and ceiling height .

knightfly · Post by **knightfly** » Wed Apr 20, 2005 6:20 pm

Asked, and answered here -

http://www.johnlsayers.com/phpBB2/viewt ... sc&start=0

Bottom of the page... Steve

AVare · Post by **AVare** » Wed Apr 20, 2005 11:30 pm

Go nto the stickies and you will find one from the NRC detailing he effect of rc on closely spaced leafs.

that is what he rc does. If you accept it, fine, if you don't , fine. Don't make the decsion without knowing the ramifications.

Andre