Browse Forums Outdoor Living 1 Apr 02, 2015 11:15 pm Hi, Firstly, this is a fantastic set of forums, which will keep me occupied for a very long time! Now to my painful problem. I had a building inspector assess a house that we purchased some time ago. He assessed our sub-floor area (the house being on concrete stumps), and found mould on the back/left brick-work of the house. He advised me that it's due to (a) insufficient airflow, and (b) drainage coming from the back/left side of the house. There is no fall moving away from the house, as the entire courtyard is paved. My property is on a slope, and I'm the one at the bottom. I have a retaining wall beyond the courtyard, which backs on the neighbouring fence. I dug one some area on the other side of the brick-work at the back of the house, and found that some of the peepholes, are covered by pavers/soil/crushed rock. I had to dig down at least 7 brick rows deep, to find AGI-DRAIN piping, which appears to run along the house. I can also see no waterproofing on the brick-work, on the outside of the house. The building inspector recommended I lay slotted PVC pipe along the back of the house, to remove water which may be pooling at the back part of the house, along with changing the slope of the backyard, so the water falls away from the house. The second part might be too hard for me to do, so I was wondering whether you might think it acceptable for me to dig up the entire back/side area 500m all the way along, clean the brick work, paint it with bitumen paint (water proofed), lay a 100mm PVC Slotted Pipe (slotted by hand drill) all along the back and side of the house, with Scorcia 20m to create a French drain. I would place the piping right next to the footer of the house - although I'm not sure on the regulation for this one). I was then hoping to have the required fall to the left side of the house, so it can be terminated to a stormwater pipe running down the entire property and on to the street. I would then back fill to the top and lay the concrete pavers right on the crushed rock again. There is a pit on the left-hand side of the house, but I'm judging that the piping won't be able to reach it as it's further towards the back of the property, and I want to try and not go towards a sump pump type setup. Would this seem OK? Would I also have to lay some additional sheeting for the concealed bricks, and footer? I'm also scared if I dig right down beside the footer, then I might can some instability somewhere, so is there a distance where the PVC pipe should be from the footer itself? I've got some photos, so you can see what I'm describing in my post:- Photo 1: * See weep hole beside downpipe which is hidden by paver/crushed rock/soil Photo 2: * See number of bricks that I dug down, along with there being no water proofing on bricks Photo 3: Photo 4: * Would I have to also lay a pipe along the small patch of dirt on the bottom right of there photo, so I go all the way around the house? Photo 5: * My pit is there which leads to a stormwater/easement to the front of my property, however I would also have to lay piping along this side of the house, as I'm seeing the same effects as the back of the house. Many Thanks to anyone who can offer some insight, or assistance with my crazy dilemma!! Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 2Apr 03, 2015 5:59 am One of the issues you have not addressed is retention of water and dampness in the wall itself. Wall will get wet and absorb water in driving rain that will gravitate down to the bottom. With no way out and without cavity ventilation and drainage water will cause permanent dampness and mould. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 3Apr 03, 2015 8:25 am Ahh, I thought that I would stop the dampness with the water proofing, and ease the water away with the French Drain, hopefully channelling the water along the footer to the Slotted PVC Pipe so it can pick up the water. My idea came from my totally untrained brain in the plumbing, and drainage area. What do you think I should do? The back runs along 6 metres or so, and the same roughly the same distance. I'm after a solution where I won't have to look at this ever again, and sometime in the future, I hope to timber deck the entire area. I've got metallic weep hole grates just underneath the doors, but is there also meant to be a clearance between those grates and the courtyard floor itself i.e. could the floor be half a brick below those grates? More importantly, do you think this is a job I could as a DIY being the plumbing/drainage part, or if not, then do you know what it could cost? Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 4Apr 03, 2015 10:10 am You are not likely to eliminate dampness just with drain in the ground and without air ventilation. Dampness will also increase your termite risk. Excavate and get rid of the dirt against brick walls and then deck the area is my tip. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 5Apr 03, 2015 4:37 pm Thanks for your advice. If you had to excavate, then how far would I need to excavate away from the brick wall? Would you dig right down to the top of the footer, or right to the bottom of the footer? Would I still put drainage there, or leave it as it is, going by the photos, with the AGI DRAIN? Now, if I wasn't going to deck the back/side for some time, then is there anything else I could do, whilst being cost-effective? Could I do the drain, and place thicker Scorcia all the way to the top, where it meets the paver, without have the paver there, to provide some aeration through the Scorcia, or am I dreaming with the fairies? Can I do the above myself as a DIY, or do I have to get a drainer/engineer/plumber to do the work for me? Speak soon, b Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 6Apr 04, 2015 6:52 am homesaw Thanks for your advice. If you had to excavate, then how far would I need to excavate away from the brick wall? Would you dig right down to the top of the footer, or right to the bottom of the footer? Would I still put drainage there, or leave it as it is, going by the photos, with the AGI DRAIN? Now, if I wasn't going to deck the back/side for some time, then is there anything else I could do, whilst being cost-effective? Could I do the drain, and place thicker Scorcia all the way to the top, where it meets the paver, without have the paver there, to provide some aeration through the Scorcia, or am I dreaming with the fairies? Can I do the above myself as a DIY, or do I have to get a drainer/engineer/plumber to do the work for me? Speak soon, b Up till now I have tried to point you in the right direction to solve your dampness problem but now you require specific advice as to extent and detail. That can only come when someone like me has visited your site and assessed what to do in the most efficient and economic way. The difference between poor advice and top advice often is measured in thousands. Poor advice (usually free advice) will cost you more than top advice And yes, none of this is rocket science and you can do DIY Cheers Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Surface Water Drainage/Mould Inside Brickwork Subfloor H 7Apr 29, 2015 12:47 am My apologies for not getting back to you sooner, as I hadn't received any emails saying that someone had replied to my post. All fixed now!!! Thanks again for the great advice. I already had a building inspector come and see me on the first inspection, so would you charge for working on a single problem, or charge for the entire fee? I also had another hitch in my master plan, to build a deck all the way around (which I could then just dig up around the house, and leave it to air for good - by your excellent advice, but after asking council about permits, it would be estimated at over $2,500!!! I estimated the materials about that much, so I guess the deck is out!! Another quick question, was that would I be able to raise existing pavers, which are already on compacted sand/soil, by just adding 50-100mm of additional sand underneath each paver and re-laying, or would I have to take all the sand out, and add more to the base (which will kill me). Thanks again in advance, This certainly doesn't look good. I would be engaging with an independent inspector to have a look at this. 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