How can I tell a crawl space leak from a soft floor caused by something else?
A floor that is soft or sagging because of a leak will usually be wet underneath and show a pattern of water along the joists. A soft floor from a worn joist or a failed beam is often dry and shows a different kind of damage. Checking the underside with a light and a meter is the surest test.
Look at the joists and the sill from the access point and note any dark stain, any soft wood that gives when pressed with a screwdriver, and any line of tide mark on the foundation. A leak leaves a fresh stain, a dried edge and a moisture gradient. Old rot tends to be dry and crumbling, with no fresh water mark.
The crew takes readings at each section of joist and records them against the floor above. A soft spot with high readings is a moisture problem. A soft spot with dry readings is a structural problem, and the crew tells you that it needs a builder or structural engineer rather than a drying plan.
What should I photograph before the crew cleans the crawl space?
Photograph the access point, the space from the hatch, each wet area, the water line on the foundation and any damaged insulation. Take a photo of the floor above from inside the house, and note the room and the position of any soft spot. These records show the condition before the work starts.
Take the photographs without moving anything, and include a reference object such as a tape measure so the size of the damage is clear. Note the time and the weather when the photographs were taken, because a wet space after a thaw looks different from one after a dry week.
Give the photographs and the notes to the crew at the start, so the record can be compared with what is found. Keep copies, because the insurer and any later contractor will want to see the condition before the drying began.
Why is insulation removed rather than dried?
Insulation that has been soaked holds water in its fibres and between its layers, and it stays wet long after the surface looks dry. It is also a place where mold can grow and where the wet material can keep the joist beneath it damp, so the crew removes soaked insulation and dries the wood beneath it.
Batt insulation sags and loses its loft when it is wet, and it does not return to its original shape. Blown insulation settles into a dense mat and can hold water in its lower layers. Neither can be dried to a reliable reading, and so the crew replaces it once the wood is dry.
The removal is done with care. The material is bagged in the space, the bags are carried out through the hatch, and the area is vacuumed before the drying equipment is set. The owner is told which insulation has been removed, so that the replacement can be sized and fitted by the right contractor.
Why does moisture keep returning to my crawl space?
A crawl space that stays damp after the leak is fixed usually has a ventilation or ground-moisture problem. The ground gives off water vapour all the time, and the space needs a ground cover and vents that let that vapour leave rather than collect.
The crew checks the vents, the ground cover and the grading outside. Vents blocked by snow, soil or landscaping cannot move air, and a ground cover that is torn or missing lets vapour rise into the space. Both are common, and both are cheap to deal with compared with the rot they can cause.
Where the humidity stays high across the space, the crew records the readings at several points. That record is what a contractor uses to decide whether the space needs a ground cover, a dehumidifier or a change to the vents.
What is the hardest part of crawl space work?
The hardest part is access. A low space with a small hatch, wires run along the joists and limited headroom all slow the work and make each reading take longer. The crew plans the route in and out before it starts, so the equipment and the removed material can move without damaging the house.
Working on the belly of a house means crouching, crawling and carrying wet material back out through a small opening. The crew takes that into account when it estimates the time, and it tells you before it starts if the access will need a larger opening or a change to the hatch.
The price follows the access. A space that is easy to reach and shallow costs less to dry than one that is low, cluttered and full of wiring. The crew explains which parts of the scope are driven by access before any work begins, and it does not put a figure on this page.
