Browse Forums General Discussion 1 Jul 10, 2015 11:04 am My IP is in Caroline Springs, Melbourne and is currenty tenanted. Soil classification Quaternary Basalti Clay classified as Highly reactive Clay Site (Class H type). Damage is to the external front of the property with cracks observed to the brick workand render, and cracking to the ceiling plaster, cornice and wall plaster of the master bedroom. I am not sure what to do. Our insurers RACV, have had 2 building inspections, 2 plumbing inspections carried out but could not determine the cause of the movement. They then engaged an engineer to report on the damages. The inspection report advised that the cracking and movement to the front entrance area of the house is typical of problems that occur due to differential settlements of the footings. In their opinion, the cracking and movement in the house has resulted due to following factors: Seasonal Changes Tree roots drying out Defferential movements between diferent footing types The engineer’s recommendations are: “We would recommend that copies of the original structural drawing be obtained to determine the footing types to the brick piers to the front of the house. Depending on the footing types, it is possible that pressure grouting methods could help stabilise th footings particularly to the front secction of the house. it is possible that the pressure grouting methods could re-level the footings to minimize the cracking. Once the footings have been stabilsied then repairs can be carried out to the interior and exterior cracking. We would also recommend that the trees growing at the front of the house (pencil pines) should be removed and more appropriate plantings installed” Based on above, RACV have denied my claim. I am not sure what to do next or how to proceed as cracks contnue to appear slowly. Any advise or help will be highly appreciated. Thank you Re: Need help with cracking and movement to IP 4Jul 11, 2015 2:25 pm Hi Kiyaora How old is your house and do you have the engineering drawings? Also photos would help? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Need help with cracking and movement to IP 5Jul 11, 2015 4:28 pm kiyaora Yes they are. That makes it slightly easier. I take it that the portico/entrance is pulling away from the rest of the house. These structures used to be designed to be on independent strip or pad footings and not part of the main slab.This practice is now rare and the portico is included in the house slab. I will make some assumptions but correct me if they are wrong. You planted immature trees after construction. Your house is about 5-7 years old. Cracks have developed in the last 24 months. 1 Take floor levels or get a copy of the engineers levels from the report. see if what they are saying is correct. 2 Remove trees (do not use resin injection before steps 2 and 3). 3 Wait 12-24 months for soil moisture to return.Your slab should rebound to some degree. 4 Take levels again to see if there has been some recovery. 5 If there is no recovery then consider re hydration, resin injection or under pinning. Re hydration is the cheapest but the least reliable method but worth a try first before resin injection or underpinning. I am familiar with the soil conditions in your area and it is possible to get rebound from the highly reactive clay in your area. You can get a independent geotechnical engineer to look at your property to confirm everything that has reported Re: Need help with cracking and movement to IP 6Jul 11, 2015 8:26 pm Racv im told from friends who deal with them regularly are just about the worst in the industry to stop claims costing them, i would not trust them as bottom line is least cost to them. Re: Need help with cracking and movement to IP 7Jul 13, 2015 9:06 am StructuralBIMGuy Hi Kiyaora How old is your house and do you have the engineering drawings? Also photos would help? Hi The house is 11 years old. I have only owned it for 2 years. I have just asked the council for the drawings etc. I will post pics shortly. Thanks Re: Need help with cracking and movement to IP 8Jul 13, 2015 9:13 am insider kiyaora Yes they are. That makes it slightly easier. I take it that the portico/entrance is pulling away from the rest of the house. These structures used to be designed to be on independent strip or pad footings and not part of the main slab.This practice is now rare and the portico is included in the house slab. I will make some assumptions but correct me if they are wrong. You planted immature trees after construction. Your house is about 5-7 years old. Cracks have developed in the last 24 months. 1 Take floor levels or get a copy of the engineers levels from the report. see if what they are saying is correct. 2 Remove trees (do not use resin injection before steps 2 and 3). 3 Wait 12-24 months for soil moisture to return.Your slab should rebound to some degree. 4 Take levels again to see if there has been some recovery. 5 If there is no recovery then consider re hydration, resin injection or under pinning. Re hydration is the cheapest but the least reliable method but worth a try first before resin injection or underpinning. I am familiar with the soil conditions in your area and it is possible to get rebound from the highly reactive clay in your area. You can get a independent geotechnical engineer to look at your property to confirm everything that has reported Hi Insider Yes you are correct. It is the entrance pulling away. The house is 11 years old . Cracks have appeared in the last 12 months. 1. The report I have from Hawthorn Consulting Engineers does not ahve any level reading on it. In fact it has no measurements or readings. Should I ask them about the readings? 2. Yes will do. 3. My tenants are about to leave. I am not sure if I will be able to lease the property out with the cracks inside the house if i leave it for 12-24 months? 4.Ok noted. 5. What is rehydration? Can you suggest an independent reliable geotechnical engineer to look a the property? Thanks for your help. Re: Need help with cracking and movement to IP 10Jul 13, 2015 10:09 am Hi Kiyaora Thanks for the photos, first observations, the cracking is substantial and there is a lot of mass in that portico? Personally i dont think you need another expert report...It's a waste of your money & Seriously, what more are they going to tell you that you dont already know? As I have said you will need the engineering drawings although I doubt the portico detail would have been engineered/built correctly with additional reinforcement & ties. Steps to follow: 1. Check to see what reinforcement was included in the portico design 2. Then drill in those locations to see if the rebar/ties was placed correctly, if not then: 3. The loads will need to be taken off the portico while you undertake the repairs 4 . These repairs will involve stabilizing the foundations, increasing the footings, pinning and reinforcing the brickwork 5. Alternatively you can pull it down in the reverse order of construction and rebuild also may I suggest articulated joints where required 6. A combination of 4 & 5 above..the engineering and construction is pretty straight foreward, located someone locally that can provide a full service, ie. inspection, engineering and repairs, all in one. goodluck Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Need help with cracking and movement to IP 11Jul 13, 2015 11:13 am Yes you can do what structuralBIMguy says but be prepared to do it again and again.If you don't remove the source of the problem then it will happen again.Your report stated that ground drying caused by trees and seasonal drying have caused the problem so you should address this first. Many repair works have failed and even increased the damage because the existing ground movement wasn't considered which in your case is drying. Remember this order. 1 Fix the source of the underlying problem(remove trees) 2 Allow for ground recovery.(12-24 months) 3 Carry out structural and cosmetic repairs(rehydration and/or underpinning or as StructuralBIMguy say reconstruction as a last resort) Re: Need help with cracking and movement to IP 14Jul 26, 2015 11:33 am kiyaora Handy007 Is the house a volume builder or custom built house? Sorry not sure who the builder is. Waiting for all the papers from council. Let us know once you have those papers. 'It's not the size of the dog in the fight, it's the size of the fight in the dog.' Have look at your house plans and you will probably find that brick articulation joint has been missed. Maximum allowable spacing is 6M or 5.5M for a wall with window… 17 20520 Are they stumps or screw piles ? How much fill is there, is the site a class "P" ? A "H2" site is not supposed to have stumps it is supposed to have grid beams according… 1 6920 House movement is always a potential problem and there is a cause. Yes you should have it inspected by a competent and experienced building consultant 2 7008 |