tunnel: seal the concrete walls and paint

[msimerson]

options

1. parge with QUIKWALL surface bonding cement or equiv.
2. penetrating concrete waterproofing sealer (quickrete, Deco Seal, etc.) a. Dayton Cure & Seal 25% (Ciro)

sealer types

Type	Life (years)	Pros / Cons
sodium silicate	permanent	reduces moisture movement through densification
lithium silicate	permanent	""
siliconate	7-10	one heavy coat
silane	7-10	works great below the surface
siloxane	7-10	works great above surface
silate / siloxane	7-10	works well above & below surface
acrylic	1-5	resin quality varies widely

References

• Foundation Armor buyers guide
• Bob Vila best concrete sealers

[msimerson]

On the recommendation of an architect and building coatings specialist for one of the Puget Sounds biggest construction firms, we went with Dowsil AllGuard, a "Silicone Elastomeric Coating." The first coat was applied Oct 18, 2022. We intend to get a second coat on as soon as weather conditions and volunteer availability permit.