skip to main content

Interior or exterior French drain

5 months ago

I’m looking for some guidance as where both online and from local contractors I’ve seen a variety of opinions.

Is an interior French drain in the basement vs external foundation waterproofing and French drain superior?

I live in a 100 year old house with a concrete foundation. So I’m concerned about moisture impacting the integrity of the foundation but I’m also not sure if that’s a practical concern (the house seems to have been fine for 100 years!). An exterior job would be significantly more complicated because there is an extension over a crawl space and 3 sets of exterior concrete steps that would either have to be demolished to do exterior waterproofing, or they have to skip those spans. We consistently get water in the basement when it rains, but not a large amount (estimating a few buckets).

We also plan on finishing the basement once we waterproof

Sort by:Oldest

Comment (1)

worthy
5 months ago
last modified: 5 months ago
Aside from the self-interest of contractors doing only interior drains, there's little question that an exterior drain is the more effective and safer course. It keeps water from further damaging the foundation while an interior drain only takes the water away, but does nothing to protect the foundation from continuing deterioration.

However, the multiple extra costs and disruption of installing an exterior drain often make it more cost effective to go the interior route.

Each job has separate considerations. For example, the elevated basement was flooding on a rental home we owned. Rather than lose and compensate the tenant as we ripped out all the finishings, we excavated four feet down; then replaced the useless clay weepers and waterproofed and insulated the foundation exterior.
Related Discussions
interior french drain with integrated vapor barrier is a good ?
Q
Comments (7)
Interior systems may keep the living area dry. But they do nothing to stop the deterioration of the wall and the underlying soil from the flow of water. I would only use an interior system where: 1) there is no access to the exterior, as in homes built on or near the lot line next to similarly situated homes; 2) the water is coming up through the basement floor; 3) foundation walls cannot be excavated without risk of collapse, e.g., rubble walls; 4) it is in conjunction with exterior water control measures.
...See More
Do Plumbers Video and Snake Out French Drains?
Q
Comments (1)
Where I live a French drain has no pipe at all. It's simply a drainage ditch that is filled with gravel or drain rock, and then sometimes covered over with soil. If that is the type of French drain you have, it's entirely possible that the drainage stone has silted up over the years.
...See More
Question Regarding French Drain
Q
Comments (2)
Sounds like you may need a soil consultant/engineer.
...See More
Question Regarding French Drain
Q
Comments (0)
Hello All I have this under irrigation, but wasn’t sure if it’s best to have it there or the basement category as it applies to both. I can delete whichever post based on everyone’s input as I’m new to this board. I recently had an addition built with a full basement. There were two areas in the corners of the addition where water was leaking in. Note that we do have a new sump in that room, but do not have the interior perimeter channel. To help solve the issue, we recently installed exterior french drains (both footing and surface) on all sides. We just had a heavy rainfall and it seemed the drain helped on one side of the addition. However, the other corner though seems to still have water leaking in. It seems to be appearing from the floor (seeping through concrete) and not the corner. Is it possible that the drains will work overtime or should I expect it them to work immediately right after they are installed? Meaning, could there be water still sitting under the foundation before the drains were installed that made it's way back in after the storm and it just takes time for that water to no longer be there? The other note is that the rest of the yard is still being graded and is currently still soil/clay. Sod is being installed as we speak, but during the storm, it was still clay. I was really hoping the exterior drains would be the final solve as we spend a decent amount to have them installed to fix the problem. Interior drains will be difficult as the room is finished. Any input is greatly appreciated. Thanks all!
...See More

Related Stories

REMODELING GUIDES Plan Your Home Remodel: The Interior Renovation Phase

By Bud Dietrich, AIA

Renovation Diary, Part 4: Peek in as the team opens a '70s ranch home to a water view, experiments with paint and chooses tile

HOUZZ TOURS Houzz Tour: Undone in the French Quarter

By Karen Egly-Thompson

Color and history abound in this ‘unrenovated’ pied-à-terre in the Big Easy

CURB APPEAL How to Update a Traditional Exterior With Color

By Eco+Historical, Inc.

Keep those historic architectural details — a few gallons of paint may be all you need to give a traditional facade a stylish new twist

DECORATING GUIDES Dip Into Chartreuse for Intoxicating Interiors

By Charmean Neithart Interiors

Somewhere between green and yellow lies alluring chartreuse, a visually powerful, amazingly versatile color for interior designs

HOUZZ TOURS My Houzz: French Colonial Mansion in India

By Wendy K. Leigh

A businessman's gracious, expansive beach house welcomes a host of international visitors

EXTERIOR COLOR Exterior Color of the Week: Tasteful Taupe

By Jennifer Ott Design

When you want to skip the peachy beiges and ubiquitous creams, consider this rich cool brown neutral instead

EXTERIORS 5 Easy Tips for Choosing Your Exterior Paint Palette

By Lisa Frederick

Make your home the talk of the neighborhood — in a good way — with an exterior paint scheme that pops

HOUZZ TOURS Houzz Tour: Wisteria and Light in the French Countryside

By Fabienne Dupuis

A stone’s throw from the gardens of Versailles, a former presbytery is now a dream weekend retreat

DOORS Interior Glass Doors Shine as Stars of the Flow

By Laura Gaskill

If your rooms are cast in a dreary light or the setting is uninspired, give glass doors a more prominent role

DECORATING GUIDES How to Get Authentic French Style in Your Home

By Twinkle and Whistle

Move over Shabby Chic and French Provincial. These myths and realities reveal the real look of French decor

More Discussions

Basement Leak After Waterproofing

3

Professional advice needed! Basement insulation

6

JBN Builders, LLC Review

1

Cold Spring Basement Renovation

0

Poker basement ideas

2