Below grade silll repair ?

[rjn2649]

The walls in my 1940's garage through the years have become, below grade because people thought if they raised the dirt around the garage it wouldn't flood. Can't make this **** up.
Current code is really limiting what I can do as far as fixing the issue properly so I have to live with a garage that gets wet at times.
I have replaced two sills with 4x4 treated. this is working where I can change the grade for better drainage.
The problem is my neighbours side. My sill is about 5" under grade, dirt is pilled against a wooden wall.
My plan is to rebuild the wall with a 6 x 6 concrete block for the first layer then a pressure treated 2x4 sill.
My question is mortar material. the blocks will have dirt against them that get wet and hold the water. I will be putting the blocks down on an existing slab. We can't change the slab, would if we could.
is there a special king of mortar that would be belter for below grade? I can pressure wash and clean the edge of the slab as needed.
Special paint/coating on the concrete blocks and mortar? How long for the morter to dry before putting the wall load back on?

Am I overthinking? (PROBABLY) The walls ands sills have probably been below grade since the 70's.

 

[BillK]

Is it wood or something else ? How far below grade ? Pictures ?

 

[Shiftless]

How did the dirt on the outside of the wall come to be above the level of the wooden sill? Have you lived there a long time and just never noticed that serious situation or ??

Regrade first. Then fix the sill. You’ll probably have to support the building from the inside section by section and cut out rotted sills and also sections of the affected wall studs.

 

[Superbowl]

Most any mortar is water proof, but after it cures you may want to seal it.

To fix your problem however, I would trench around the garage and fill with gravel after installing a membrane like roofing ice guard to the bottom of the walls. Hopefully you can trench or pipe to grade so the water naturally flows away. If a gravity drain is not possible, there are two options.

1. Dig up a larger area of yard and fill with gravel (cover with landscaping fabric and dirt to plant grass) making a French drain to hold rain water until it seeps into the dirt under the gravel.

2. Install a sump pump. Such sump pumps are best put inside the garage to keep debris out and protect from freezing so you will have to chisle a hole in the slab and go through or under the wall foundation so water from the outside gravel can reach the pump.