For my Roland TD27 i needed a rather small platform that just fit into the corner of my room. And i wanted the throne not to be on top of it. So after taking the measures i ended up with 148 x 88 cm. From the local hardware store i got the most stable plate of wood for this, which is Multiplex 21mm. Several glued layers of wood make this best against vibration and bending.
So the weight of my platform was about to be 72,7 kg. This includes the plate, a thin anti vibration mat (got it from the hardware store as well), a thin drum carpet and the drumkit.
First i was interested in how the weight is distributed approximately. To find out i put the plate on 4 books (they have to be the same size), one of them in each corner. Then i placed the drumkit on the plate. Next i used a simple body scale to measure the pressure at each corner, replacing one book at a time. This way i found out that the corners in the back each carry around 26,5% of the weight, the front corners carry around 23,5%.
The Sylomer pads are 13,0 x 13,0 cm sized. They are of type SR11 and should carry 19 kg each to do their work. It is important to not overload or underload them. I ordered 5 of them.
To carry 72,7 kg i would need 3,82 Pads. As i wanted to place half a pad in the middle of the platform (to prevent bending), there was only 3,32 Pads necessary for the 4 corners anymore. 3,32 divided by 4 makes 0,83. So i cut one of my pads in half (for the middle) and the other ones i cut 17% away from each, so they ended up being 13,0 x 10,8 cm.
As the 4 corner pads are the same size, i placed the middle pad a bit more backwards to consider the weight distribution i found out with the body scale.
Then on the upside of the platform i placed the anti vibration mat. Without it, the kick drum would resonate a bit with the large wood plate, amplifying the noise in my room. On top of the mat comes the carpet. I attached both with a few tiny stripes of double-side tape.
And basically that was it. It fit into the corner of my room quite nicely. The height of the platform is just 5 cm. The volume in the room is still the same, but there is almost no vibration going into the floor anymore.
In case i want to extend my drumkit some day, i keep the spare parts of the Sylomer. The half pad should carry 9,5 kg, and the 13,0 x 2,2 cm stripes should carry approximately 3 kg each. If i need it, i just stick one or two of them next to the middle pad under the podest.