For visual effect, I have decided to board over the bottom half on my paint damaged garage internal wall with shiplap. We have had damp problems moreso on one side of the garage, as pictured on the rendered wall. I am thinking the moisture is coming from outside, where we have approx 3mts concrete path with steps to a metre high, with expansion tape installed alongside the house. When it rains heavily, I am guessing the water is entering via the gap below the expansion tape? I only thought about the outside recently, and am wondering if the above sounds logical? Could the rain saturate the ground under the expansion tape, creating moisture on the internal single brick rendered walls? Apparently, all was waterproofed when the house was built, but who knows? Question 1. If I were to use expanding silicone, and put the expansion tape back in if possible, would this create enough barrier to prevent water coming into the garage (if my guess is correct)? Its a single brick, rendered wall. Our home is built utilising the natural slope of the land wherever possible using steps. Some parts of the wall externally, have the pathway and steps around 11/2 mt plus higher than the garage floor, and down to almost around 20cm as the level changes in other sections. Where most of the moisture has come in, coincides with the height of the section outside from what I can see. For the most part, I am guessing the water saturates the ground and finds the exit point and saturates the bricks? The damp areas tends to start at the ground level, and some areas have crept up the wall in other sections. We have recently epoxied the floor, including 100mls up the wall, hoping to create a moisture barrier inside the garage where the concrete meets the walls. I guess this is the easiest point of water causing damage .. where the wall meets the concrete. We now have the preexisting issue of the flaking paint and/or fluorescence on the rendered wall. Question 2. If I remove all the flaking or damaged paint (but not all the paint on the wall) and treat with a moisture product in the affected areas, install flexible silicone outside, will this help my problem? The shiplap will be attached to timber framework, with a 3cm gap around the whole base, so air can circulate? Question 3. Do I use a sander or grinder to remove the flaking, damaged paint? If so, what grit do I purchase to do the wall? Is removing all the paint from the walls necessary, or can I do the affected areas only? The height of the shiplap will be 1.5m height with a negative damp product (was recommended, Crommelins DampStop), so hoping someone can help answering my questions before I go to a lot of trouble? Thankyou.
floor level.
1200 height up the wall.
