Rigid Insulation For Slab On Grade

Water resistant rigid board for under concrete slab insulation and slab support in traffic bearing applications.

Rigid insulation for slab on grade.

Get free shipping on qualified under slab foam board insulation or buy online pick up in store today in the building materials department. Continuous insulation is defined in 90 1 as insulation that is continuous across all structural members without thermal bridges other than fasteners and service. The f factors for slab on grade floors are defined in standard 90 1. I wouldn t go as far as saying you couldn t use spray foam below a slab but i m not sure why you d want to.

Moisture control is provided by a vapor retarder under the slab. Consult appendix a table a6 3 1 in the 2016 edition for a tabulation of assembly f factors for slab on grade floors based on the arrangement and rated r value of the applied insulation. Spray foam for sure has uses where it is the best choice by a long shot but under a slab is not the place. It also discusses installation procedures for below grade and under slab insulation.

Insulating a slab on grade can be expensive. Rigid insulation is placed vertically on the exterior face of the foundation wall. In climate zones 4 and 5 the code requires certain slabs below grade slabs that are less than 12 in. Figure 4 11 illustrates a slab on grade foundation with a masonry foundation wall.

Set your store to see local availability add to cart. Two common rigid foam insulations specified for below grade applications are expanded polystyrene eps and extruded polystyrene xps. Materials suitable for below grade insulation are limited to rigid foam high density spray foam and rockwool boards. This insulation aligns with rigid foam sheathing that covers the framed walls above grade.

2015 iecc irc section r402 2 10 n1102 2 10 slab on grade floors. When building a slab on grade eps rigid foam insulation is the most common choice of insulation for performance and cost. Below grade under slab with foamular xps insulation. An easy way to recognize eps on the jobsite is that it is commonly white.

Slab is one foot or less below grade r 10 insulation required extending 2 feet below grade for climate zones 4 and 5 4 feet below grade for climate zone 6 insulation should extend downward from the top of the slab with two options to reduce slab edge insulation r value exterior slab insulation must be protected 46. If the slab has hydronic tubing the minimum r value of this insulation increases to r 15. This may leave a significant thermal. While standard building codes typically require insulating value ranging from r 10 to r 15 detailing around the perimeter is generally weak.

These f factors are acceptable for all slab on grade floors but you need to make sure.