Fox 1
How to Design a Building for Passive Survivability
Does EPS ‘off gas’?
EPS does not off-gas. Fox Blocks forms do not and nev­er have con­tained any CFC or HCFC prod­ucts. The forms are made by a steam process that uti­lizes pen­tene gas’ as a blow­ing agent. The blow­ing agent dis­si­pates from the prod­uct with­in 48 hours of man­u­fac­tur­ing. Fox Blocks forms are odor­less, do not dete­ri­o­rate, and do not off gas.
Does EPS absorb water?
No, EPS is a closed cell foam and does not act like a sponge or absorb water.
Does the EPS provide support for a wood sill plate?
No, the EPS has no struc­tur­al capac­i­ty to sup­port any loads. Wood sill plates must achieve the required bear­ing from the con­crete with­in the ICF. A wood plate that can­tilevers 13 over the EPS and bears 23 on the con­crete is allow­able. This can be done with a min­i­mum 2 x 6 plate. If a 24 plate is required, a taper top form should be used to extend the con­crete under the plate.
When is a Taper Top form required?
Taper Top forms are specif­i­cal­ly designed to pro­vide a larg­er bear­ing sur­face along the top of the wall. Typ­i­cal­ly, the increased bear­ing sur­face may be used to sup­port mason­ry, floor or roof loads. Taper top forms are used in the tran­si­tion from ICF to wood frame con­struc­tion and the taper top form would be the top form on the wall.
Does expanded polystyrene (EPS) present a serious fire hazard?
The EPS in an Fox Blocks has a flame retar­dant that allows the forms to be flame resis­tant. The EPS will melt when exposed to sus­tained tem­per­a­tures over 300°F (149°C). The igni­tion point of the melt­ed styrene is 600°F (315°C) (wood is approx­i­mate­ly 500°F (260°C). Fox Blocks have been test­ed to meet the build­ing code require­ments for flame spread and smoke devel­op­ment, plus Fox Blocks may be used as fire resis­tant rat­ed wall assem­blies in schools and hos­pi­tals.