I'm new to the forum and have limited DIY experience so please bear with me!
Several years ago I had decking put down. Before decking, the render was hacked off near the bottom, and the exposed brick painted black with what I assume was something bituminous. I was told the render needed hacking away to stop the damp course being bridged. To be honest I don't know if there is a DPC, I can't see evidence of one.
I've taken up some decking and the brick work looks in pretty bad shape. Some of the holes are pretty large / deep. I don't know if it was damaged taking off the render, or water penetration over the years. The decking edges were flush to the brick in some places, which I've been told could cause issues, so I've cut them back to leave a gap.
I've attached a few photos. I'm sorry that I had to rotate them verticaly, it's the only way I could upload them.
I have some questions I was hoping you could help with please:
1. Should I re-point / repair with a lime based mortar (house is older than 1900), or is this not recommended because if a DPC exists, it will be bridged? 2. If I do re-point / repair, would I paint over with a fresh coat of bitumen, or is it this that's causing the actual issue by trapping moisture?
Even though this course of bricks is below the decking and it technically doesn't matter what the end result looks like, I would like to do a decent job and hopefully learn something very useful in the process.
Unfortunately I can't check for signs of damp inside as there are kitchen units in front.
I would repoint the brickwork with a mix of sand lime and cement 4.1.1 then repaint the area with aquapruff buitumin paint. The paint helps to repel any surface water from the brickwork and sealing it from damp penetration
Thanks for your reply, I really appreciate it! I just have a few questions please:
1. In case I can't get small amounts of the raw materials (it's only a small area), would a ready mix lime mortar be suitable please? For example 3.5 NHL hydraulic (TBH I don't fully understand this technical data in the context of what I'm trying to repair, so please bear with me!)
2. As well as re-pointing the deeper gaps and damage in PIC#2, would I re-point the long joint in PIC #1 immediately below the exterior render? I've read that this could bridge a DPC, if there is one. I'm not sure there is one TBH, or if this is anything to worry about?
if you go to a builders merchants they usually have broken bags of cement lime etc, you can buy 1 bag of sand, you can also buy waterproof addative for your mix, which I recommend As for the pointing, fill in any areas you can, the DPC is usually located at the bottom of the door casing height. The buitumin will stop any damp penetrating, and damp will only rise to a maximum height of 150mm.