# Sheathing tape on reclaimed XPS



## VonTed (Feb 6, 2013)

I decided to go the route of using reclaimed XPS for my interior insulation. (2" XPS). After washing, scrubbing and cleaning these panels as best I could they are still quite dirty - but I don't think I can reasonably get them any cleaner. I don't particularly mind the grime because they will all be behind a wall anyway...


However - how "sticky" should the sheathing tape be when applied? I am concerned that the dirt and dust left may leave me with an inadequate seal after applying the sheathing tape. I just tested a piece it once applied it seems to lift off easier than I was imagining.

This is a "clean panel" - I have cleaned it up a bit better than seen, but it does give you an idea of what the panels look like.









And this is the tape I bought.
http://www.amazon.com/gp/product/B000BQNZ28/ref=oh_details_o02_s01_i02?ie=UTF8&psc=1


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## Gary in WA (Mar 11, 2009)

Try some fiberglass tape with furnace mastic over it or canned foam as the tape tends to work loose from the foamboard over time; http://www.buildingscience.com/documents/published-articles/pa-foam-shrinks
Though aged may make a difference...

Gary


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## VonTed (Feb 6, 2013)

Go with just foam or foam over the tape? Or could I skip the tape if I caulk or foam the seams and edges?


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## Gary in WA (Mar 11, 2009)

Canned foam alone at the edges, including top/bottom to completely air-seal the concrete from the basement air against condensation. As mastic/mesh tape is easier to see any pinholes in front of you, I suggested it over canned foam. Remember to fire-stop every 10' horizontally and at the ceiling/floor level to stop fire from getting in any floor joist cavities; http://publicecodes.citation.com/icod/irc/2006f2/icod_irc_2006f2_6_sec002_par018.htm
Use positive fasteners through f.b. into concrete. Add 1/2 f.b. under wood p.t. (if required by local AHJ) plate (for thermal/air/capillary break), air-seal/insulate the wood rim joists; http://www.buildingscience.com/docu...joist/files/bscinfo_408_critical_seal_rev.pdf

ADA the drywall; http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/

Gary


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