Template:All systems - INSULATION
Template:All systems - INSULATION
Contents
1 General
Only RGC Accepted insulations, specifically listed by membrane manufacturers in the RPM as acceptable for use with their modified bituminous loose laid, or mechanically attached base sheets, may be used without an overlay board in the RGC Guarantee Program.
2 Material Selection
TBA
2.1 Polyisocyanurate Insulation
Only polyisocyanurate insulation with non-organic facers(e.g. fibreglass) are acceptable for use in the RGC guarantee program. In addition, manufacturers’ product identification labels are required for all Polyisocyanurate insulation packaging and the date of manufacture must be provided on all product labels.
3 Application
3.1 Mechanical Fastening
3.1.1 Application to Steel Decks
- When installing insulation or thermal barriers to steel decks, all edges of the first layer of insulation or thermal barrier shall be fully or intermittently supported by the deck. Mechanical fasteners must penetrate steel decks a minimum of 20mm (3/4") and must be located in the top flutes only. The minimum thickness of insulation directly over fluted steel decks shall be a minimum of one-half the nominal flute width. Additionally, the minimum allowable thickness of expanded polystyrene or unfaced glass fibre insulation shall be 38 mm (1-1/2"), and the minimum thickness for extruded polystyrene, faced glass fibre, faced polyisocyanurate, etc. shall be 25 mm (1").(For loose laid ballasted systems, see Section reference needed)
3.1.2 Minimum Screw and Plate Fasteners
- Minimum fasteners using Screws and Plastic or Steel Stress Plates: (see Section 3.8.5.2)
Insulation Board Size Field Perimeter Corner 600 mm x 1200 mm (2'x4') 4 4 5 600 mm x 2400 mm (2'x8') 5 6 8 900 mm x 1200 mm (3'x4') 4 6 7 1200 mm x 1200 mm (4'x4') 5 6 8 1200 mm x 1800 mm (4'x6') 6 8 12 1200 mm x 2400 mm (4'x8') 8 12 15
3.1.3 Minimum Nail Fasteners
Minimum fasteners using Accepted Nails (Wood Decks Only): (see Section 3.8.5.2)
| Insulation Board Size | Field | Perimeter | Corner |
|---|---|---|---|
| 600 mm x 1200 mm (2'x4') | 5 | 5 | 6 |
| 600 mm x 2400 mm (2'x8') | 8 | 10 | 12 |
| 900 mm x 1200 mm (3'x4') | 6 | 8 | 10 |
| 1200 mm x 1200 mm (4'x4') | 6 | 8 | 10 |
| 1200 mm x 1800 mm (4'x6') | 8 | 10 | 14 |
| 1200 mm x 2400 mm (4'x8') | 12 | 16 | 18 |
When conventionally adhered roof assemblies are installed, (adhered, hot asphalt mopped, torched, etc.), all insulation must be mechanically fastened to all nailable decks including steel, with exceptions as per (reference here). The upper layer or overlay in a multiple-layer insulation application does not require mechanical fastening. The exception is for slopes exceeding 1:12 (1" in 12") or steeper - in those cases, the upper layer must be fastened.
When using multiple layers of plastic foam insulation the layers shall be mechanically fastened, whenever possible, as if they are a single layer. Alternately, when the use of mechanical fasteners is not feasible, or multiple layered assemblies require mechanical fastening of the base layer only, or decks are constructed of non-nailable materials (concrete,) polyurethane foam adhesives may be utilized to adhere insulation layers to one another, to other insulations, or substrates. Only polyurethane foam adhesives that are specifically listed as acceptable by the insulation manufacturer may be used. Extruded polystyrene insulation must have planed faces (removal of smooth surface) when adhered with polyurethane foam adhesive.
The roof area is divided into three areas (zones). The perimeter area is defined as 10% of the building width or 40% of the building height, whichever is less. In no case will perimeter area be less than 2.0 m (7'). The field area is defined as the remaining area after the perimeter is calculated. When the roof height is:• greater than 18 m (60’) and low-slope (slope is 2:12 or less) or• less than 18 m (60’) and pitched (slope is greater than 2:12), Perimeter fastening along the entire eave will be enhanced to corner requirements. The corner area is defined by the perimeter in both directions at the corners. In no case will the corner area be less than 2.0 m x 2.0 m (7’ x7’).
For corner enhancement of roofs in high wind locations (higher than 100 mph) or for roofs above 60’ refer to Section (reference here).
NOTE: To qualify for a RoofStar Guarantee, and to comply with the Guarantee Standards in 4.6 (below) , mechanically attached insulated membrane systems must be fastened according to each manufacturer’s tested specifications conforming to CSA A123.21-14 Standard for assembly wind ratings.
The upper layer or overlay in a multiple-layer insulation application does not require mechanical fastening. If mechanical fastening to concrete decking is required proprietary concrete fasteners and plates must be used.
Acceptable nail types: Shank-and-head or head-plate nails with minimum 25 mm (1")nominal head size. Head-plate nails with solidly attached plate to ensure plate cannot slide down on shank.
Cavity deck or T Deck may be defined as either nailable or non-nailable, depending on profile and deflection.
Nailing is permitted on wood decks only where insulation thickness does not exceed 50 mm (2"). Nails with a minimum 25 mm (1") head size or greater are required for insulation and overlay boards fastened to wood decks. Nails to be placed a maximum 600 mm (24") o/c in each direction and be of sufficient length to penetrate the underlying sheathing a minimum of 20 mm (3/4") or in the case of plywood, completely through the sheathing.
When insulation and or cover boards are installed under mechanically fastened membrane systems the membrane manufacturer’s tested and approved fastener layout patterns shall be followed. In addition, the minimum number of fasteners with plates for insulation and or cover boards, under mechanically fastened membranes, shall be six (6) fasteners for 1200mm x 2400mm (4ft. x 8ft,) board sizes and four (4) fasteners for all other smaller board sizes.
For all adhered asphaltic membranes, ie: hot asphalt, torch welded, or cold adhesive applied roof assemblies:
On all heat sensitive insulations (polystyrene; extruded and expanded), an overlay consisting of two layers of acceptable cover board is to be installed when using hot asphalt as an adhesive, or where the cover board is less than 1/2" in thickness on torch applied assemblies.
Two layer system: Fasten the first layer of cover board, offsetting the joints from those of the insulation. Tape the joints before applying the second layer, offsetting the joints from both layers below. Alternatively, all layers of cover board and insulation may be fastened as a group.
Single layer system: Flame protection under or over the cover board is required. Seal over all board joints and wall transitions with membrane manufacturer's approved self-adhered membrane tape. Alternatively, a full layer of minimum No. 25 asphalt coated fiberglass base sheet conforming to CAN/CSA-A123.16-04 (R2009), Type II or No. 30 non-perforated felt conforming to CSA A123.3-05 (R2010) may be used under the cover board.
Composite board insulations with factory applied base sheets that utilize self-adhering seams for flame protection, are mechanically attached over decks listed by the membrane manufacturer, and specifically accepted by RGC, may be installed as a single layer overlay board over heat sensitive insulations.
Minimum Fasteners for Overlay Boards are: 1200 mm x 2400 mm (4' x 8')
| Using: | Field | Perimeter | Corner |
|---|---|---|---|
| Screws and Plastic or Steel Stress Plates | 8 | 12 | 15 |
| Accepted Nails (Wood Deck Only) | 12 | 16 | 18 |
| Fastener layout patterns and other board dimensions | (See Section 3.8.5.2) | ||
Heat Insensitive Insulation Only: In the case of heat insensitive insulations, one layer of acceptable overlay board is required. For hot asphalt applied roof assemblies the insulation is to be mechanically fastened before an acceptable overlay board is fully mopped to the insulation. Alternatively, manufacturers proprietary insulation adhesives may be used to adhere accepted overlay boards to insulations. When hot asphalt or adhesives are not used in a roof assembly accepted insulation and overlay board(s) may, as a group, be mechanically fastened directly to nailable decks including steel.
3.2 Adhering Insulation
When foam plastic insulation is adhered (with hot asphalt or compatible adhesive) in a roof assembly, the insulation board size shall be a maximum 1200 mm (4') in any direction.
Only RGC accepted overlay boards may be installed by the back mop and flop application method over heat sensitive foam plastic insulation boards. Heat insensitive insulation boards, (e.g. Polyisocyanurate) are not permitted to be installed with this method.
Asphalt or paraffin-impregnated coated fibreboard roof insulation, used as an insulation overlay board must be asphalt-coated on the top and bottom surface (minimum coated two-sides) when adhered (in a roof assembly) with hot asphalt or asphaltic based adhesive.
Proprietary adhesive applied insulation/overlay board membrane systems accepted and installed in the RoofStar Guarantee Program shall conform to the CSA A123.21-10 Standard test method for the dynamic wind uplift resistance of adhesive attached membrane roofing systems and/or the Factory Mutual I-90 Listing for adhesive attached assemblies.
The roof system must be as per the complete tested assembly and a calculation for the building wind load requirements using the Wind-RCI calculator or RoofNav as applicable be submitted with project documents.