Help - fixing loose mortar on bottom course of wall

[commonman00]

I hope someone can give some advice with this problem.

I have noticed recently that my garage floor is wet after the recent storm in Melbourne. I found out that water has come in come into the garage through the bottom of the wall (where the bottom course meets the garage floor). It appears that the mortar joining the garage door and the first/bottom course bricks is loose and water is sipping through. The garage floor is concrete and bricks are laid on top of the concrete floor.

I tried tab on the bricks on the first few courses from the base and it appears that none of the brick is loose. Running my finger through the mortar I can feel that the mortar is loose.

My questions:
1. What is the best way to fix the loose mortar?
2. What caused the mortar to loosen in the first place. The house was built about 7 years ago, so I am a bit surprised that the mortar has loosened. The other side of the wall is a garden bed, so I am guessing that it might be the reason.

Your advise is greatly appreciated.

[MikeT]

Just a DIY hacker but I'll have a go.

I assume where you say garage door you meant floor.

I doubt the mortar is loose all the way through (and for much of the course) - I'd be worried about the integrity of the wall if it was. Probably the reason why the mortar is loose though is because of the water. Mortar will let damp through and over time affect it's integrity. Perhaps laying on improperly cleaned concrete slab might make it prone to allow water through - not sure.

Fixing the mortar won't fix the problem long term I suspect.

A couple of questions.
Is the garden bed built up against the wall outside. Not a real good practice (though my garage is like that - being built into a hill steep and back filled.)
Is it single brick - that'll make the sepage worse, though if the garden beds built up and it's double brick it means termite ingress will be hidden.

If you can, I'd try to dig the garden bed down below the level of the floor so any water will run elsewhere. If not can you modify the terrain somewhat to make a lot of the runoff go elsewhere. If not, and you can at least dig down perhaps there's a way to poor a small concrete wall, tieing in to the slab below, with bond crete added for water proofing.

Re the mortar, how much have you dug out to see how bad it is. A hammer drill will work only so far from the floor side because it's on the slab - but outside will allow you to clean it out. Otherwise a cold chisel scoring the floor to help anything you put back in to bind. Re replacing what's loose - if you're stuck with the water trying to get in then I'd dig out an inch deep all the way along that section and ... someone may say there's some new fangled sealer you can use - otherwise add a bit of bondcrete to the mortar to help it seal but I can't see you ever getting a seal that will stop all water/dampness unless you attack it from the outside.

As I say - that's the advice of a hacker.

[MikeT]

Oh - didn't mention the obvious, if it is built up and you can't remove the garden but can dig down next to the wall - put some/more agg pipe and gravel in to help drain it away - and avoidplants with extensive roots.

[commonman00]

Thanks MikeT.

I was able to inspect the wall today.

The mortar is not loose all the way through. From inside the garage, I brushed away the loose stuff and I found the solid/hard mortar about 5-10mm in. From outside (the garden bed) the story isn't too good. There is quite a lot of loose mortar that can be pushed out. Fortunately, this only occurs on some section of the wall which probably suggests that that part of the slab was not cleaned properly prior to laying the bricks.

The garden bed is againsts the wall. The mulch level slightly above the slab. So today, I digged out some soil to make sure that the final level is slightly lower than the slab. Hopefully that should help.

[Joister]

hi ya commonman00

not sure if the following helps but did a similar fix-it-job at my dad's place a year or so ago - or what sounds like a similar fix job (a little different in that he was having problem with water running in off a slab and creating a water film in an adjoining room - whereas your's sounds like it is running in off a garden)

i scrapped out the loose morter and re-pointed the bricks (put in a new mortar); i then put some sikaflex at the join between the outside slab and where bricks joined slab - i'd then painted on a water proof membrane

seems to have held so far with no water getting through to the other side (i.e. into the room) - i needed all these bits and pieces for other jobs so not sure if you can grab yourself similar materials for smaller jobs and thereby make it a bit more economical (would assume you can and sikaflex is always handy)

anyways like i said above hope this helps - good luck