External vs Internal Basement Waterproofing

torontotim wrote: ↑
If exterior is only $10K more than interior waterproofing, I'd go exterior. But I'd want to know it was solved before I continued finishing the basement. I'd also go with a Dricore or similar subfloor system, proper floor drains etc.

torontotim wrote: ↑ External waterproofing for a 30 x 18 foot property is only $15K? What does that include? Seems too cheap frankly, unless it's a semi-detached and there's only one 30 foot side to deal with.

I suppose in a 100 year old property, whatever damage the water is going to do has been done unless something has changed on the exterior to cause the leaking more recently. So an interior solution would be fine.

How deep is the basement? What is your finished ceiling height going to be? I ask as I began finishing my basement almost 20 years ago in my 100+ year old Toronto home, and ended up with ceiling heights a little under 7 feet. It's fine for us and for what we use the basement for (TV and my home office), but obviously the ceilings are a little low.

If I had waited and put more money aside, I would have had the basement dug out / underpinned. Would have cost $50K or whatever, but given the 5-6x increase in value of the house in the 23 years I've owned it, the $50K is meaningless and would have been a great investment. If I had 8 foot ceilings in the basement, and had spent money on installing egress windows at the front/rear (I'm only 3 feet from the neighbour on the side where there are windows so window wells etc. become a challenge if not an impossibility) I could easily have turned this into a legal basement apartment which would add a ton of value to the house.

If exterior is only $10K more than interior waterproofing, I'd go exterior. But I'd want to know it was solved before I continued finishing the basement. I'd also go with a Dricore or similar subfloor system, proper floor drains etc.

My clay pipes are fine BTW - I had them scoped, had the drains/bathroom rough-ins redone at the one end by the main stack (new 25 years ago) but they connect to the original clay drain pipe running to the city sewer. It's in perfect condition. But again, if I could turn back time, I might have looked into digging the basement down and redoing the drain line etc while I was at it.

Ordeal wrote: ↑ It ‘s a semi. They will dig about 4.5 feet.

torontotim wrote: ↑ OK - what are the other details on the exterior quote? Do they specify what exactly they will do to fix any cracks in the foundation, then apply a liquid membrane, then a rigid membrane, installation of weeping tiles etc etc etc?

To my knowledge, these old homes don't have any sort of weeping tile system at the base of the foundation. I've never had a waterproofing quote for this house, but I would expect the water needs to go 'somewhere'. So if it's all directed to the base of the foundation, and there's no weeping tile system, then it's just going to pool there and cause problems.

This is one advantage of an interior system, and perhaps why they may be pushing for that. With an interior system, the water is directed to a newly installed set of drain pipes around the perimeter of the basement which slope towards a sump pit. Then the collected water is pumped up and out of the house in a controlled manner.

I have no idea where an exterior weeping tile system would drain to as a retro-fit on a Toronto semi to be honest.

How close are you to your neighbour? That's another issue with an exterior solution - chances are you're digging up your neighbour's foundation as well. Like I say, in my case I'm about 3 feet wall to wall, so to dig up my foundation would mean to remove all the material between our houses. Then with my luck, my neighbour starts having water issues in their basement after the work is done and blames me.

So... a few points in favour of an interior system I suppose as a retro-fit in a close-quarters situation. I can see the advantage of going that route and saving $10K to boot. Just be clear on what they're doing. The principles are similar - the water is channeled down the wall into a drain system around the perimeter of the basement all directed to a central point where it is collected and removed.

I had a house with water issues out in the country back in the mid 1990's. 1200 sq ft bungalow with a nice deep basement. But in the rainy season, we would get inches of water in one area. I cut a hole in the slab, dug out a pit and installed a sump pit to collect the water and then pump it out. It was all DIY - I didn't have the $$$ to do it right. Sold the house after 5 years with the water issue written into the agreement and walked away from it.

exrcoupe wrote: ↑ @Ordeal how deep is your basement? You may not have a weeping tile, but I don't get only going down 4.5 feet if your basement is deeper than that.

torontotim wrote: ↑ Toronto semi-detached homes like OP's often have shallow basements. Mine is about the same - 4-5 feet or so deep, with about 2-3 feet above grade. I have 4 steps up to my front porch then another step up into the entry door. Only about 7 feet of finished ceiling height in the basement once I added a subfloor system and put drywall on the ceiling.

exrcoupe wrote: ↑ @Ordeal how deep is your basement? You may not have a weeping tile, but I don't get only going down 4.5 feet if your basement is deeper than that.

I went with Aquatech waterproofing as well. They worked REALLY fast and were done in about 5 days. They dug down to the weeping tile and replaced the old busted clay ones. I actually had them add Durospan GPS insulation on the outside before they backfilled it. I bought the insulation and they just put it in at an incremental cost. My basement now has more insulation in/along the walls than the rest of my house now. The irony.


Waterproofing1.jpg



Waterproofing2.jpg


In that picture, they screwed up the initial insulation placement, but in the end it does come all the way up to the waterproofing line in the end, just doesn't show in that picture.

Wilmega wrote: ↑ When do you know it's time to get water proofing? My house is about 60-70 years old, had some recent leaks in the cold room which was right below our porch (concrete steps).

torontotim wrote: ↑ If that's the worst you've had in 60-70 years, then you don't need to waterproof. What you likely need to do is divert water from the area above your cold room.

Most foundation water problems are solved by diverting water, not digging up the foundation and waterproofing.

I'd start a new thread for your specific problem and include lots of photos from inside and out.

Wilmega wrote: ↑ When do you know it's time to get water proofing? My house is about 60-70 years old, had some recent leaks in the cold room which was right below our porch (concrete steps).

random pattern wrote: ↑ In an ideal world would you do both? Or overkill?