Cladding through exterior insulation: designed support, interfaces and shared sequence
An apartment elevation is using continuous steel girts where the received detail shows intermittent thermally improved clips. The proposed change has not been reviewed for loads, thermal effects or membrane connections.
The cladding attachment is part of both the support path and the envelope detail. BC Housing’s third-edition wall guide describes screws through strapping and insulation, proprietary clips, and other support approaches with different thermal effects. Its structural guidance has a defined scope. Use the received project solution and current product literature rather than assuming a guide table covers every wall, wind load and cladding weight.
Make the attachment sequence a shared detail
- Locate the designed support path. Identify the actual wall, cladding, attachment and backing references for each elevation. Establish which trade sets the anchors, clips, strapping or girts and who reviews the work. Keep the required structural and envelope decisions together. A clip sold as thermally improved still needs to suit the loads and geometry; a familiar screw does not establish permitted embedment or spacing.
- Check the board and connection interaction. Review the required insulation thickness, fitting around attachments, relevant compression and membrane-penetration details. Confirm how the current assembly handles openings, flashings and drainage. Ask the responsible reviewer about an obstruction or mismatch before cutting extra gaps. Avoid claiming an unchanged label R-value means a changed support system has unchanged effective wall performance.
- Agree a suitable first-area sequence. Coordinate substrate readiness, attachment setting, board placement and receiving checks between the cladding and insulation teams. Identify evidence needed before later layers hide anchors or membrane connections. Record the accepted arrangement and its references. The goal is a workable repeated method, not forcing either crew to invent an alternate connection to meet an assumed daily output.
- Refer changes and retain the actual answer. Describe a proposed alternate girt, clip, fastener or spacing with its location and affected interfaces. Obtain appropriate technical review before procurement or installation proceeds as a substitution. Record changed requirements and distinguish corrected, accepted and unresolved areas. A discussion about thermal loss does not itself authorize a crew to redesign the attachment or remove installed structural components.
Common mistakes
- Applying a guide table outside its stated wall scope.
- Calling nominal board R-value the effective wall value.
- Cutting clearance gaps to avoid an unresolved detail.
- Treating a thermal concern as authority to redesign support.
Checklist
The shared attachment detail identifies
- Actual support path and current project references.
- Required structural and thermal review responsibilities.
- Board fit and membrane-penetration provisions.
- Received first-area sequence and concealed checks.
- Approved changes and the status of affected locations.
Check your understanding
The new girt supports the cladding, so can it replace the specified clips?
Show the answer
Refer the actual change for structural, thermal and interface review with its location and product evidence. Apparent support alone does not establish equivalence to the specified connection or authorize the substitution.
