... to have adequate bracing underneath to prevent sagging, or placed on top of say a plywood sub-base. It deteriorates in damp conditions, but who would build a layout in damp conditions? The same is said of MDF and I've never had problems. Suspect the poor reputation is from people just having baseboard framing around the edges and no cross-bracing. posted: 16 May 2017 03:35 from: Rick It's a lot of fun and very easy to set up jigs for building turnouts with a Templot template. 2_171952_510000000.jpg posted: 17 May 2017 23:59 from: Tony W Hi Stuart. At the risk of hijacking this thread, I too have recently purchased a large quantity of Sundeala board for my new layout project as my inexperience with it has much to commend it. It does need more than adequate support and in spite what is recommended on the instruction sheet that comes with it, I would not countenance a greater unsupported span than 12" to avoid sagging. It is certainly more sound absorbing than plywood. My previous layout ...