Posts

There’s inevitably water in the ground around a basement, and, because cement-based walls and floors are porous, water will seep through them if it can go nowhere else. This water could be from rain filtering downwards, groundwater seeping horizontally through the strata, or a water table pressing upwards.

Here in Toronto, many basements have chronic water problems and there are several solutions to cure the condition, depending on the type of water problem present.  While we usually recommend an exterior approach to waterproofing, sometimes that is not an option.  In that situation, installing an interior weeping tile system in your basement can be a safe and proven alternative.

When this water comes up against a basement wall or floor, it applies hydrostatic pressure that can be surprisingly powerful. If it can’t find a way through, it pools against the outside bottom of the basement walls, and gradually saturates the inside surface if there’s nowhere else to go.  While an interior weeping tile system will not waterproof your basement, will will effectively manage the water entering your basement and channel it away so you never see it.

Exterior Weeping Tilesinstalling interior weeping tile

The traditional method of preventing this is to install a drainage system along the outside bottom of the basement walls. These days this comprises of a plastic pipe typically 40mm in diameter and with holes punched into it along the length. This is wrapped in a water-permeable sheet to keep the dirt out, and then buried at a gently sloping angle leading to a discharge point.

Unfortunately these “weeping tiles” as they are called (the name’s a reference to past building practice) may become clogged as time passes. When that happens, the ground water switches to “Plan B” – that is, it accumulates until the hydrostatic pressure is high enough to find a way into the basement.

What to Do About the Water

Gravel to fill in weeping tile system in Toronto home

You cannot keep water back from the inside of a basement, at least not permanently. This means you either have to excavate, and replace the failed exterior weeping tiles or you have to allow the water to seep through, and then remove it continuously. Canadian homeowners often view the latter as the better of two evils. That’s okay, as long as you’re not using your basement as a living space.

This is obviously not an ideal solution. In fact we recommend you replace the outside system if all possible. Unfortunately, sometimes accessing the outside perimeter of a basement isn’t possible, that’s when an interior weeping tile system comes into play. Installing an interior weeping tile system isn’t a DIY project, as you can see from the steps below.

STEP 1: Break out a trench all around the room. This needs to be around eighteen inches from the walls, and to bottom out below the footings.
STEP 2: Lay in the weeping tile as we described, cover it with gravel and re-pour the floor

STEP 3: Create a sump at the bottom end of the run of weeping tile, and install an automatic electric sump pump to carry the water away before it overflows. Fit a lid so it looks a tidier.

 

How It Works

Finished weeping tile system in Toronto basement

Water always gravitates down to the lowest point. The weeping tiles attract it like a magnet. It’s taken away before it rises to above the footings. The result’s a perfectly dry basement inside, provided you hired a professional who’s registered, and knows what they are doing. While installing an interior weeping tile system is not the ideal solution for a dry basement, it’s great alternative when an exterior system is not available.

If you live in Toronto or the surrounding GTA and have questions about installing an interior weeping tile system, you can contact Nusite waterproofing today.  We offer a free in-home estimate and inspection of your basement and will work with you to choose the best waterproofing solution for your home and your budget.

French Drains in Your Home

French Drains have nothing at all to do with France. Their name comes from Henry Flagg French from Concord, Massachusetts, who invented them in 1859. In simplest terms, they are trenches filled with gravel that act as conduits for water runoff. They remain popular ways to remove unwanted water from our basements, as Mr. French originally intended.

anatomy of a french drain system

What’s in a Name?

French drains used to have other names like weeping tile drains, soakaways, rock drains, rubble drains, perimeter drains and even French ditches. These terms originally described the different methods of constructing them. These days, the term “French Drain” applies almost universally, although not all French Drains follow the same design. They all do exactly the same thing though, and that’s to lead water away when it’s not wanted.

Methods of Construction

Before the advent of Henry Flagg French, people dug ditches to take water where they wanted it. These ditches had two disadvantages. They became blocked. Moreover, livestock and people fell into them (and sometimes even drowned). Boarding them over changed nothing except that it became more difficult to clear the stoppages.

Mr. French stumbled over the idea of filling drainage trenches with medium-sized stones. This solved both ditch problems simultaneously because:

  •   Blockages occurred at the entry point and were cleared easily
  •   There was no longer a hole to fall into

The final stage was to fill in over the stones with compacted earth (or even concrete). After that, people seldom even knew the French Drains were there.

drawing of how a french drain system works

Getting the Water into the Drain

This is not as daft as it sounds. When you allow the surface water to enter the drain naturally from the top using gravity feed, there’s a good chance of it backing up in unusually wet conditions and blocking easily. Engineers solved this problem by introducing perforated pipes inserted into the stone fill. That way, if the water started backing up it simply moved back up the tube.

French Drains also drain soggy ground like bogs and marshland. In this case, the builders apply permeable membranes along the length before they add the stones. Water can then enter the trench at any point along the length, greatly increasing the efficiency of absorption while reducing the possibility of blockages from the sides.

What to Fill French Drains With

You can fill a French Drain with almost anything provided it doesn’t rot, holds back a potential blockage and allows the water to filter through. Material can be anything from gravel through broken bricks and tiles to natural stones. It’s customary to use larger pieces in the center, because this speeds up the flow of water.

French Drains in Our Homes

French Drains are present in many Canadian homes, although their owners may be unaware of them. Common applications include:

  •  Placing them just outside external walls to prevent water ingress
  •  Positioning them under floors to prevent water upwelling
  •  Installing them inside basements, in which case the water flows to a sump pump

Despite the best intentions in the world, nothing lasts forever. Older French Drains do clog up eventually especially where permeable membranes are absent. The symptom of this happening is the gradually appearance of groundwater. The solution is to call in an expert to open them up, clean them out, and then reinstate them professionally.

Do you live in Toronto or the surrounding GTA?  Contact us today for a free on-site inspection and estimate.

REFERENCE

http://en.wikipedia.org/wiki/French_drain