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Tigard Waterproofing

Interior drains and wall liners

Basement waterproofing in Tigard

Interior waterproofing does not stop water reaching the wall. It gives the water an easy path to a pump before it reaches your floor.

Call (503) 555-0120

The pattern that points to this job

After a long wet spell a dark band appears along the bottom of one or more walls. Sometimes water beads up through the joint where the slab meets the wall. Boxes stored against that wall have soft bottoms.

That pattern means the soil outside is full and water is pushing in low down, along a length of wall. Patching one spot moves it a few feet along. A drain that runs the length of the wall takes the pressure off instead.

Where the drain sits

How an interior drain collects water at the edge of a basement floorA cut-away block drawing: wet soil sits against a foundation wall. Inside, a liner on the wall leads down to a trench of stone with a drain pipe beside the footing, covered by a patched strip of floor. The pipe runs to a sump pit.Wet soil against the wallWall linerSump pitFloor patched over the trenchStone and drain pipeFooting
Water that reaches the wall runs down behind the liner into a trench of stone. A perforated pipe in the stone carries it along the wall to the sump pit, and the floor is patched over the top.

How the work usually runs

  1. Clear the wall

    Stored things come away from the wall. In a finished basement the bottom of the drywall and the framing plate may have to come out along the wet side.

  2. Cut the floor

    A strip of slab roughly a foot wide is broken out beside the wall and the spoil is carried out in buckets.

  3. Lay stone and pipe

    The trench is sloped toward the pit, lined with washed stone and a perforated pipe, and inspection ports are left so the pipe can be flushed later.

  4. Line the wall and close up

    A sheet or dimpled panel is fixed to the wall so seepage drops into the trench. New concrete goes over the stone, level with the old floor.

What it does to your house while it happens

Breaking concrete indoors is loud and dusty. Ask how the rest of the house is sealed off and whether the furnace or air handler in the basement will be covered or shut down.

The patched strip stays a different color from the old slab. If you plan new flooring, tell the company so the patch is finished flat enough to take it.

A drain needs somewhere to send its water, so this job nearly always comes with a sump pump. Where the pump's pipe ends outside is covered in the Tigard drainage guide.

Worth asking before you agree

  • Which walls get a drain, and why not the others?
  • Will the wall liner be left visible, or can a finished wall go back in front of it?
  • How do I flush the pipe if it silts up, and where are the ports?
  • What happens to the radon vent or floor drain if the trench crosses it?

Interior drain questions

Does an interior drain weaken the floor?

The strip is refilled with concrete. Ask how thick the patch will be and whether it is tied to the old slab.

Will the wall still look damp afterwards?

It can. The liner hides the wall and catches the water, but the masonry behind it stays wet in winter. Stopping water before it reaches the wall is exterior work.

Ready to have someone look at it?

Describe what you are seeing and where in the house it is. The company on the phone will tell you whether it is work they take on and when they could come out.

Get a waterproofing company on the phone

For homeowners with water coming into a basement or crawl space, or a yard that drains toward the house.

Call (503) 555-0120

Calls can be recorded. Read how the referral is paid for and what happens to your details.

Call (503) 555-0120