Filling in a 150mm hole in continuos concrete wall

mtbotrev, Feb 25, 9:30am
Hi. our garage flooded after Gita. One of the reasons is a 150mm hole through the continuous concrete wall foundation for house to a spa pool under a deck on outside. Spa is redundant so it is being removed but today I need to cut the empty water pipes and fix the hole. Hole is about 50mm off ground

Will standard concrete mix work. I have cement and builders mix?. ratio.? Needs to be dry enough to be as non porous but still needs to hold. I was going to put a piece of ply held in place on in side and backfill from spa side.

One problem is a power cable to spa which we think is made safe but Im not going to chance it. it will be cemented in as well as I need to do job today(and not wait for an electrician to check it) in case a repeat happens.

Thoughts on concrete mix?

Thanx
krames, Feb 25, 10:44am
is the power cable running through a sleve conduit ?
Any mix will be fine as its not going to add to the foundation strength anyway with the hole being cut into it previously
mtbotrev, Feb 25, 10:56am
Hi. no its just a white cable about 8mm thick.

Thanx re mix strength.
krames, Feb 25, 11:17am
you need to put a sleeve on the outside of it so if you remove it later it eill come out easy and you dont want concrete against it it
p.monro, Feb 25, 11:50am
Try a dry mix. If you can sieve the large stones out of the aggregate then use cement say 1in 4 and a little water so that the mix sticks together but does not run. Pack this into the hole. Yoy may choose to plaster over it when it is set.
If you can not sieve then use the builders mix without sieving
sprinter51, Feb 25, 11:52am
OP you have lived at that address for XYZ years and how many times have you been flooded

Gita came only once
mtbotrev, Feb 25, 12:15pm
Fair call. 3 years. Flooded once but not thru that hole so although I was "aware" there was a hole(about 100mm above spa floor) I didn't proactively fix it. Doing so now thanx.

Parts of rest of wall that are not accessible seem porous at times(last time when it rained for about 3 days straight about 2 years ago. Part also came in under garage door channel which I will be deepening as well now.
mtbotrev, Feb 25, 12:17pm
Hi. I have rechecked and there is a sleeve. so I will concrete that in place as I want to deal to it today then pull cable thru when made safe later this week and then concrete in ends.
mtbotrev, Feb 25, 12:19pm
Thanx. Will leave it less than proud then and plaster both sides to get smooth finish. Cant be too dry tho I spose as it will be more porous?
budgel, Dec 19, 11:00am
When you go to patch the hole, use a spray bottle to dampen all around the hole so the dry existing wall doesnt suck the moisture out of your mix.
Hydraulic cement expands as it dries. Cemix quick plug is a brand available in NZ.