Browse Forums General Discussion 1 Apr 10, 2016 11:31 pm I have a 100 year old sandstone cottage in Stepney (adj. Norwood), Adelaide and on the driveway side of the house I have constant cracking in various room. I fix it and within 6 months they reappear (not huge cracks but enough to be annoying to look at). I would like some good advice on a solution e.g. underpinning options (there are a few these days) or maybe it has something to do with a big tree in backyard (but don't understand why this would only affect one side of house) or drainage etc. Can anyone recommend a structural engineer or the like who has provided good advice (and what this advice cost). Also interested to hear if the advice was implemented and if it worked. I suspect underpinning is the solution but want to make sure I'm not overlooking what maybe a simpler less costly solution. Re: Walls cracking advice, Adelaide eastern suburbs 2Apr 11, 2016 9:42 am Hi Les_step Some photos and more (supplementary) info would help? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Walls cracking advice, Adelaide eastern suburbs 3Apr 13, 2016 5:23 pm Here are some pics example cracks - it occurs in all rooms on the driveway side only here https://goo.gl/photos/HgS7YxmbbDBL39fBA The cracks are obviously not that bad (last repaired 18 months earlier) although some go from inside to outside. Of particualr concern is that it seems the front of the house (with double windows) each year moves more towards the road (each year where the the cornice joins the wall there is 5mm movement, over 10 years that is a lot). Whether is it just moving back and forth I can't judge. Re: Walls cracking advice, Adelaide eastern suburbs 4Apr 13, 2016 7:29 pm Hi Les_step Thanks for the photos.. Just curious have you re-pointed the original mortar in any places with a stronger cement based mortar, I am guessing the original mortar was weaker lime based mortar? Anyway you are correct with underpinning I think you will find the original foundations are inadequate have you pulled up a portion of the paving to inspect below ground? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Walls cracking advice, Adelaide eastern suburbs 5Apr 13, 2016 9:33 pm ive never repointed the mortar, not sure if this has been done in the past, haven't looked under the pavers either. what would i be looking for? Yes, typical of these houses is poor foundations (sits on bluestone). strange that only 1 side of house has issues. Re: Walls cracking advice, Adelaide eastern suburbs 6Apr 14, 2016 7:28 pm les_step ive never repointed the mortar, not sure if this has been done in the past, Try a scratch test, Lime mortar is fairly soft, if its been re-pointed with a harder cement based mortar it will not scratch easily Also the cracking pattern over the windows suggest it may have been repointed les_step haven't looked under the pavers either. what would i be looking for? Yes, typical of these houses is poor foundations (sits on bluestone). What you may find typical of old houses of that era, is that the stone work looks great above the ground, or within view, etc.. & generally what is out of sight is substandard, a plinth also hides a multitude of poor workmanship if you get my gist?.You will need to assess the quality of the stone work, mortar and cracking below the ground. les_step strange that only 1 side of house has issues. No doubt the drive way side and gardens at the front and back are the issue at first glance..what state are the pavers in ..does the drive way dip? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Walls cracking advice, Adelaide eastern suburbs 7Apr 17, 2016 6:23 pm Hi Les_step I noticed that there is a tree behind your house how far away is that tree and what size. Is it the back left corner that is showing signs of cracking? The issue could be caused by the tree drying the soil and foundation settlement but more information (more photos) and info about the tree is needed. Re: Walls cracking advice, Adelaide eastern suburbs 8Apr 18, 2016 2:58 am Yes there is a very big tree in garden. It has crossed my mind if this was part of the issue however then I would have expected it to damage the non driveway back corner as well, as this is closer than the front part of house with issues? I've added two more pics (https://goo.gl/photos/HgS7YxmbbDBL39fBA). The floor plan shows where tree is in back yard (it's 12m from closet house corner). The red dots are where there is cracking or cornice pulling away from ceiling. There is also a photo of tree taken from next to kitchen. Re: Walls cracking advice, Adelaide eastern suburbs 9Apr 18, 2016 6:14 am Your bathroom and kitchen are on the driveway side. Has anyone looked under the floor for plumbing leaks? 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: Walls cracking advice, Adelaide eastern suburbs 10Apr 18, 2016 7:39 am Unfortunately photos can only take you so far.. then you need to collect data and run multiphysics simulations in order to replicate the same effects in a model, the repairs are reversed engineered with the appropriate optimized solutions included.When I get back ill see if I can put up some other masonry examples and solutions on the below link.hth Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Walls cracking advice, Adelaide eastern suburbs 11Apr 18, 2016 4:04 pm Appreciate all the feedback, not attempting to find a solution online but looking for a referral of someone who can come over and take a look ie structural engineer. Have never looked at bathroom plumbing but bathroom is new and cracking been an issue for long time. Re: Walls cracking advice, Adelaide eastern suburbs 12Apr 18, 2016 7:18 pm les_step Yes there is a very big tree in garden. It has crossed my mind if this was part of the issue however then I would have expected it to damage the non driveway back corner as well, as this is closer than the front part of house with issues? I've added two more pics (https://goo.gl/photos/HgS7YxmbbDBL39fBA). The floor plan shows where tree is in back yard (it's 12m from closet house corner). The red dots are where there is cracking or cornice pulling away from ceiling. There is also a photo of tree taken from next to kitchen. Often the tree roots will follow along the footing so the damage can occur along way from the tree area and I noticed that your Air con along the side discharges onto the ground this would also attract tree roots. As BE said it could be a plumbing issue as well.You need floor levels to determine if the footings are settling.If you want in the mean time you can try a rough test yourself. Get a marble and place in the middle of your Kitchen, bathroom or siting area which every has floor boards or tiles.Watch if it runs to the outside wall. Re: Walls cracking advice, Adelaide eastern suburbs 13Apr 18, 2016 7:50 pm Older buildings may have pitted water pipes with spray irrigating sub floor. Water pressure test may confirm or rule out drop of water pressure. 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: Walls cracking advice, Adelaide eastern suburbs 14May 21, 2016 6:57 pm StructuralBIMGuy Hi Les_step Thanks for the photos.. Just curious have you re-pointed the original mortar in any places with a stronger cement based mortar, I am guessing the original mortar was weaker lime based mortar? Generally the opposite is true. Mortar high in lime naturally re-hydrates sealing cracks in mortar. As its a 100 year old sandstone building it was probably made with a lime:sand mortar mix [L1:S3] See section 3.3.6 Lime http://thinkbrick.blob.core.windows.net ... asonry.pdf Housing today uses slabs and strip footing as non deflective beams supporting the entire wall. With wirecut bricks used with mortar mixes high in cement and now lower with lime there is little allowance for movement. Expansion joints generally take up the slack if there is any. Mortar cracking nowadays is rather permanent when it occurs as unfortunately most brickies now lay an M4 mortar mix. StructuralBIMGuy Anyway you are correct with underpinning I think you will find the original foundations are inadequate have you pulled up a portion of the paving to inspect below ground? As the cracking is weaving through the mortar around the rock from top to bottom, I'd ask what is your strip footing? I've seen 100yr old cottages with nothing but bluestone block slabs as footings. The pressed bricks moved over time separating from the bed joint and it had been repointed in the past to allow for the movement. In the SW side where the prevailing weather hit the house, moisture allowed gradual but constant hydration of the lime mortar giving less cracking than the NE side. Remember the original construction of a 100yr old cottage didn't have a driveway [no cars] so the ground will have more water on one side and less on the driveway side. This causes shrinkage and movement....so cracking can develop. Beautiful house...and good luck finding a cure. Being a builder is more than just having once held a hammer. It's about the trades you hire and ensuring that they give a result that meets the industry standard and the home owners expectations. 1 6630 10 15745 Thanks for your reply! We're definitely not after a small house Might still have a chat to them. Who did you end up building with if you don't mind me asking? 2 2621 |