undergrade waterproofing

[koykoy]

fellows, may I ask for your suggestion on undergrade waterproofing specifically used on basement walls? my masons suggested sahara but I dont know if it is the most effective. are there new technologies or products today that are more effective?

though mine is not really for the basement. i just started constructing a house on a front sloping lot so the back wall is already undergrade. my concern is undergrade flowing water though im not so sure if it is really that much considering that the soil in my lot is lime/limestone (anopog) and very very hard and compact.

btw, the topsoil at the backwall exterior will be covered with concrete for a distance of around 2 meters to minimize the water flowing down so my concern really is the horizontal flow of water underneath. or in the first place, should this be a matter of concern? ::)

[bboncan]

hi kokoy, yes you will need waterproofing. sahara is an integral type waterproofing meaning it works within the concrete. it will get in between concrete pores. how closed are the pores i really do not know. but it is commonly used so it must be working. it is effective for low pressure hydro-static pressures. but once the concrete cracks which is normal in the philippines given the seismic conditions there goes the sahara. so, as long as the concrete does not crack, sahara is good.

you need actually a positive-side (outside) waterproofing to block water before it gets in. there are many products in the market which claims excellent results and most of them perform but a good product is only as good as the applicator.

[2diy4]

I also had the same problem in my old house in Posadas village. What I did before the soil was backfilled in the basement, was to apply some waterproofing mortar on the hollowblock walls. But the real trick was that after the waterproofed wall was built, I built another wall about 1 foot away from the waterproofed wall, and this was what held the soil. On the bottom of the two walls, I placed some perforated PVC pipe, which drained to the side of the house that did not have the backfill. Then, the space between the two walls was filled with 1" gravel.

The theory was that any moisture that exited from the retained earth will be drained through the gravel and to the drainage pipe. The strategy was a success, and the wall stayed dry for the 10 years I stayed in the house.

[Bobby]

I used to use sahara for waterproofing of our old basement and it used to work fine (that was in the 80's, so long time na). But in the latter part of the 90's un may super typhoon dumaan, i found my basement flooded waist deep. After draining all the water out, i used sahara integrated to my cement plaster but found out na hindi na nakaka waterproof ito ng mabuti.

So, searching the market for an alternative waterproofing, i found out that a contractor advised me to use superseal mixed with acrybond and paint it on all walls and floors ng basement and it worked. Until now, walang kahit isang tagas. I bought it at ortigas hard in shaw blvd near edsa shangrila before.

And yes, un pvc pipe idea is a good alternative too but for me na di na pwede gumawa ng another wall, i used superseal na lang.

:)

[jessie2]

If your backwall exterior has a 2 meter concrete flooring then that means your backwall does not have any direct contact with the soil? So your worry would then be water seeping up from the flooring. Is that it?

I would follow 2diy4's suggestion of putting a 4 inch perforated pvc pipe on your back wall that drains to the side (or around to the front). What I did though in my case before filling it in with gravel was to place garden cloth on top of the perforations. This prevents your pipe from getting clogged up later on. I would also suggest connecting a cleanout pipe to it for future maintenance.

As an added measure, I would suggest that you lay a heavy grade plastic sheeting before you pour in your first floor concrete (I assume it's going to be concrete).

Of course, a cement additive would also be an added security.

[2diy4]

The plastic under the concrete poured on grade is a very good idea. It prevents moisture from wicking in from the ground. You need this if you intend to put in a parquet, vinyl or laminate floor. Even a tile floor will look better, as moisture from the ground may cause some tiles to appear different in color, resulting in the tiles looking like a map.

[koykoy]

thanks for all the replies.

i noticed some waterproofing additives says it is flexible. does this mean ba na if concrete moves and cracks, the waterproofing stays?

would have wanted to use sahara but am concerned if the wall moves over time...

[opzuk4x4]

Water Plug for cracks then Thoroseal with acryl 60 for the walls. Dont forget the perforated PVC pipe, very effective, serves as a weep hole.

[bigdeal]

cool

[Kenji211]

Nagpatayo ako ng bahay. Ang lesson basta may semento, maglagay ng waterproofing additive. Okay ang sahara, pero mas okay ang superseal. O ung kristol. Same technology ata.

The plastic lining is good.

[Bobby]

Yes, superseal is more effective in waterproofing below grade structures like basements. You can call ortigas hardware at 631-4059 for more details. Dont forget to use acrybond with it to activate the waterproofing properties of superseal.