Crawl space encapsulation transforms your crawl space from a damp, vented area into a clean, dry, controlled environment. Think of it as “sealing up” your crawl space to keep moisture out.
benefits
Crawl space encapsulation prevents:
Musty odors in the house,
high humidity,
floors from sagging and become uneven,
pest infestations,
energy bills from growing,
mold or mildew,
cold air from freezing floors,
water intrusions.
Encapsulation also improve air quality by preventing moisture and allergens coming through the crawl space.
drowbacks:
odors like cat smell (loose weight barrier, it has to be removed, cause if water will stagnate underneath it would transfer smell) reinforced vapor barrier can give this smell, so use solid vapor barrier. The Cat pee smell comes from adhesives used in some vapor barriers regardless of fibers and textures, so even if companies selling reinforced laminated vapor barriers saying they improved this aspect - they dont.
wood shrinkage it reportedly happens when the humidity in that space dips too low for extended periods, like despite the dump crawl space in some regions there is overly dry air in winter (heater “helps” too), so wood shrinks, people usually use hvac humidifiers to prevent it, we had installed flooring in two buildings close to each other, the only difference was one of them had humidifier, so their wood flooring did not shrank. gaps in hardwood flooring inside the home, cause if the wood was not aclimate right or if it was installed dry but on the wet flooring, then it would be bigger and after you bring your crawl space in order with encapsulation the wood flooring can have gaps, but that’s not a problem of crawl space encapsulation. it can be off from milimiters to gaps. you can not change it, but listen, it is not a problem of encapsulation, encapsulation actually fixes the moisture problem, it is flooring done bad. gaps in doors, same as a floors, gaps when door meet the framing or underneath. You house isn’t wet anymore. Cause in the south floors are pretty wet. Also as for solid wood floorings, no matter humidity in the interrior or crawl space it will cup in high ambient RH and gap in low ambient RH.
floor supporting jack posts or sister joists also strugle from this, you need to get rid of moisture first and then install support jacks.
squicky floors is another thing, if you installed plywood when it was moist or hardwood, then after it dryout the floor will have gaps and it will create a slight squicking sound
overall most of the people we know who got humidity under control think those are small drawbacks compared to all the benefits.
The 8 Essential Components
Floor Vapor Barrier
Heavy plastic sheeting covers 100% of the crawl space floor
All seams must be sealed - no gaps allowed
This stops moisture from coming up through the ground
Wall Vapor Barrier
Plastic sheeting covers all foundation walls
Goes from the floor up to where the walls meet your house
Must be properly attached and sealed at all edges
Complete Air Sealing
Every crack, gap, and hole must be sealed
Includes around pipes, wires, and where walls meet
Creates an airtight boundary
Moisture Control System
Usually a dehumidifier designed for crawl spaces
Keeps humidity below 60% year-round
Must be properly sized for your space
Proper Drainage
Water must be directed away from your foundation
May need a sump pump if water problems exist
No standing water allowed
Insulation/Thermal Barrier
Either insulate the walls OR the floor above (not both)
Keeps the space at a reasonable temperature
Helps with energy efficiency
Safe Air Quality
System must not create carbon monoxide or other safety issues
Regular monitoring may be needed
Proper ventilation if fuel-burning appliances are present
Integration with Your Home’s HVAC
Must work properly with your heating and cooling system
May require adjustments to your existing equipment
Should not cause comfort problems
FAQ:
Will encapsulation of walls send moisture to the wood the wood on top of the foundation walls?
No it would not, cause there will be no moisture, dehumidifier and pressure treated lumber with sealed top block will prevent moisture to go to the wood. If you already have dump crawl space, then you need to dehumidify the space and get moisture out of wood first, then sodablast the wood and treat it with anabec.
Should I encapsualte before renovating the home any further?
Yes, it is better to deal with humidity, especially if you already have moisture in the crawl space.
Does encapsulation reduce noise from outside sources?
The way we encapsulate does reduce outside noise because we focus on insulating the foundation walls air sealing the subfloor and even installing rim joist when possible so yes it can reduce outside noise.
Do I need to adress mold before encapsulation
Yes, you should. Cause otherwise you will just make things worse, mold can grow on vapor barrier.