Does EPS absorb water?
No, EPS is a closed cell foam and does not act like a sponge or absorb water.
Do I have to finish my basement walls with drywall?
All build­ing codes in the USA and Cana­da spec­i­fy that plas­tic insu­la­tion (EPS) must be cov­ered by a ther­mal bar­ri­er equiv­a­lent to 15 min­utes of fire pro­tec­tion in hab­it­able spaces. If the base­ment is clas­si­fied as hab­it­able space, then gyp­sum board must be applied but does have to taped and filled. Check with your local build­ing offi­cial.
When can I backfill the foundation wall?
The con­crete must cure for a min­i­mum of 7 days and the foun­da­tion wall must be lat­er­al­ly sup­port­ed, mean­ing the floor sys­tem is installed sup­port­ing the top of the wall. All below grade water­proof­ing / damp­proof­ing must be installed.
How do you control voids in the wall?
The con­crete mix is a high slump 5″- 6.5″ (125 mm – 165 mm) with a small­er aggre­gate size so the con­crete flows eas­i­ly. The per­son in charge of plac­ing the con­crete should watch the con­crete flow through­out the whole wall to ensure there are no void pock­ets. Inter­nal vibrat­ing pro­vides good con­sol­i­da­tion, elim­i­nat­ing voids.
Can masonry be installed on the exterior walls?
Yes, Fox Blocks has a brick ledge form and the xLer­a­tor ledge rein­force­ment that is designed to sup­port mason­ry. Fox blocks also has a tieKey acces­so­ry which is a specif­i­cal­ly made as a mason­ry tie, to be insert­ed through the form into the con­crete.
Is a vapor barrier required on the inside face of an ICF wall?
No. The char­ac­ter­is­tics of an ICF wall with the mass con­crete and the EPS insu­la­tion pro­vide the required vapor per­me­ance to meet build­ing code require­ments as a vapor bar­ri­er.
Can I install a 16' garage door and / or large openings in a concrete wall?
Yes, if the fol­low­ing cri­te­ria is avail­able for the design of a con­crete lin­tel (beam) over the open­ing – con­crete lin­tel depth min­i­mum 16″ (400 mm) or more with no point loads. Larg­er open­ings would require an engi­neered design.
Is there a problem when placing concrete, dropping concrete from the top of the wall which may be over 8' (2.4 m)?
No. Spec­i­fi­ca­tions in the Amer­i­ca Con­crete Insti­tute (ACI) do not lim­it the max­i­mum dis­tance con­crete can free fall. Engi­neer­ing stud­ies and reports have shown that free fall from up to 35′ doesn’t reduce con­crete qual­i­ty and there is no evi­dence of seg­re­ga­tion or weak­ened con­crete strength. ICF con­crete design calls for a high slump mix which assists in reduc­ing seg­re­ga­tion.
What size and how much steel reinforcement is required in an ICF?

Fox Blocks walls are designed as rein­forced con­crete walls, with steel rein­force­ment bars spec­i­fied to be installed ver­ti­cal­ly and hor­i­zon­tal­ly, as the walls are built. Typ­i­cal rein­force­ment bar sizes used are #4 or #5 (10 m or 15 m).

How do I protect the ICFs below grade?

All ICF walls below grade, that have hab­it­able space on one side (base­ment), must have a water­proof­ing / damp­proof­ing mem­brane installed. For walls that do not have hab­it­able space on one side (crawl space, frost walls, etc.) the EPS can be left exposed to the earth. The EPS will not dete­ri­o­rate when exposed to the earth.