Common Causes For Residential Building Failures

The A/OverviewThis document is designed to give customers of property protection an idea of the most common types of building defects in buildings that can be found in AS 4349.1 inspection.This list gives the reader a basic overview of the more common defects, and the reader should be aware that there are thousands of forms of architectural defects.The items we list are just more common items.B/abstract the report lists some of the more common residential building failures, including the causes, based on the case studies conducted by the author as a licensed builder.The author also includes some reasons for the failure.The purpose of this report is to provide the reader with an overview of the types of residential building failures and recommended remedies for these defects.Methods this report is presented as a case study based on the author\'s experience and personal records as a licensed builder over the past 15 years.The findings appear to me that a large part of the structural building failures listed in this report are caused by poor rain management around the premises resulting in the movement of the premises.The rest of the faults are caused by poor construction practice and poor maintenance.C/introduction the most common form of building failure noted during the AS 4349.The author\'s house inspection in Adelaide is as follows.The edge of the plate moistens this is the horizontal entry of water and salt in the soil solution, and the soil enters the edge of the Foundation through the capillary action of the concrete (the suction caused by the concrete.This is caused by many factors, including the concrete pushing the Fortecon film down in the form of edges before pouring the floor, and the cement concrete in the foundation is relatively poor (many engineers require 32 MPA concrete to resist salt entry, instead of the 20 to 25 MPA currently used), when the concrete edge shape is not placed low enough to prevent horizontal pouring, concrete pouring causes water to accumulate on the top surface of the pouring, thus forming a pool.The ultimate reason is that there is no plastic film between the pavement and the base edge.While the possible damage caused by this problem includes mildew and decay on the lower side of the interior floor covering, concrete attacks the cement matrix through the hydraulic action of the inside and outside through salt.(Salt crystals expand in the concrete matrix, resulting in cracking of the concrete ).Wall damp rise This is similar to the salt moisture described in detail below.The main difference is that salt water humidity is usually a decomposition of 90 to 100% of the wall wet process, while rising humidity is a partial failure of the wet process, partial failure usually means that damage to brick and stone walls is not as severe as wet salt water.It is very likely that the rising humidity will be found in most households before 1950, and the rising humidity may be limited to the erosion range of mortar joints, from the original surface erosion of 1 to 2mm.Salt wet is also the same treatment method.However, the customer should be aware that, in most cases, the increased humidity is not seen as very slow erosion of masonry, it may take 50 years for the mortar to erode the face of the bricklayer from 4mm deep.If the damage is not very large, I would advise the customer to monitor this.The salt humidity in the wall is caused by the vertical entry of moisture and salt into the wall, which may cause friction on the wall and will not be able to withstand structural loads.The damage to masonry is due to the expansion of salt crystals inside the masonry, resulting in the wear of bricks and mortar.In some cases, wet salt water can make masonry unstable.This is caused by many factors, including the complete breakdown of the wet process (the house before 1910 had asphalt or asphalt between the Foundation and the bricks, which became fragile as it grew older ), laying or rendering bridges on wet roads can also lead to this.Breacher piece failure in shower this is where breacher pieces fail through metal fatigue through thousands of thermal cycles inside the wall (this is where the cold and hot water inside the wall meets during the shower ).Water then flows into the wall.In general, every 25 to 30 years or so, it is common for a Breche piece to fail in the shower.The story sign of a breacher that has been replaced is two different tiles on the wall of the shower.In the inspection conducted by the property protection company, the company used an electronic humidity meter to investigate the walls of wet areas in its advanced report to determine this defect.The high humidity on the wall next to the shower usually indicates that it is leaking.Brick growth cracks on old residential walls may have brick growth cracks, which usually occur at the end of the wall in a vertical plane.Clay bricks actually expand because they are porous.If there is no control seam on the wall of a house, the brick can apply a compression load to each other, resulting in cracking.Clay roof tiles fired clay roof tiles can be annoyed when exposed to moisture for a long time, which usually occurs in the circle of tiles.Due to the salt attack on the tiles, the tiles will also worry in the seaside environment.It is not uncommon to see these roof tiles rub on the circle below the roof tile.As these tiles age, they also become very brittle and prone to cracking.In most cases they need to be replaced in the short term when the tiles are worn out.Concrete cancer in foundation and prefabricated concrete beams.This happens when the steel bars inside the concrete rust due to moisture/salt/carbide entering the concrete.They expand when the steel bars rust, causing the concrete to crack.This may cause cracking of the surrounding concrete members.The customer should realize that it is very expensive to fix this defect.Tree damage while some roots can cause hydraulic damage to the elements of the root physically moving building, most building failures are caused by the extraction of moisture from the soil by the trees.This causes the soil to shrink, which can cause the elements of the building to fall or move.Over the years, in numerous inspections, the author observed that when a tree was too close to the bottom of the wall, the wall and base foot would fall or move due to soil shrinkage.In most cases, the author will advise the client to keep the big tree away from the house.If this is not possible, the root fabric that does not penetrate can be used to prevent the roots from growing under the house.When a sink, rain pipe, and downpipe spills/leaks cause the soil around and below the foundation to be saturated, rain damage and soil movement are caused.Once the soil is saturated, it loses its ability to withstand the load, and the soil may collapse, causing the building elements to fall or move.In some cases, the active soil also expands, causing cracking.This then places the lifted load on the House, which can also lead to significant cracking and movement.In Adelaide, active (fine soil, such as clay) can be found at the bottom of the foothills, and fine silt flows from the mountains.The fine soil can be used in General Ross Trevor, Athelstone and Campbell.Lack of pavement around the outside.This may result in the expansion and contraction of the soil around the foundation, resulting in the movement of buildings.That is, after heavy rain, it expands in the soil and shrinks in the soil in summer.In some cases, the shrinkage of the soil under the Foundation (external part) causes the foundation to rotate on the outside when it drops.The author has seen a lot of this happening, which leads to the whole wall being tilted outward or inward.(Bow at the bottom and then tilt at the top ).In this case, it is usually necessary to tear down the walls and rebuild them.In many Property Protection reports, you may see a note detailing the sealing clearance at the foundation laying connection.Many of the houses inspected by the company have gaps at this intersection, which allows moisture to enter under the House and under the pavement.When water enters under two elements, it erodes the soil or causes the soil to expand or shrink.In this case, the gap should be sealed with a flexible sealant.Old-fashioned wiring.Over the years, the author has seen the following electrical faults in the inspection., -Power cables coated with canvas and vulcanization rubber.First of all, the canvas can be eaten by rodents, or it can only age on the body, causing the cable to be exposed, resulting in a fire.The same happens with the old rubber cable that can be split.-There is no power cord in the pipe in contact with the steel frame.I.e.If the cable is damaged, the frame becomes charged.Over the years, some houses have been inspected by property protection agencies and new wires have been found in all areas of the House, but not inside the existing hard plaster.During the senior house inspection, the company used a high-power torch to identify Wall patches and wall chase.An existing house that has no wall chasing above the light switch and power point usually indicates that the original line has not been removed.In this case, the Property Protection Society advises the client to hire an electrician to investigate the house to confirm whether the lines in these areas are original or not.The hard plaster cannot be removed during the house inspection, as this is not usually approved by the supplier.Pipe leakage in wet areas is usually caused by corrosion of lead or galvanized scrap pipes under the floor or on the floor.This will cause a leak when the pipe is corroded, and the leak will wash away the sub-filler in the floor leading to the floor and/or the floor where the base foot falls.It is very expensive to repair, because in general, the pipe is thrown into the floor in the wet area and needs to be hammer with a jack.This is a common defect because of the large number of houses that were poured into the floor by galvanized steel pipes in the properties prior to 1970.For these steel pipes, it is not whether it needs to be replaced, but when it needs to be replaced.Although there is no drainage as they should have done, this steel pipe has been in operation for many years until funds are found to replace them.If you have steel scrap and/or water supply pipes in the house before 1970 and you are considering a wet zone renovation with new tiles etc, we strongly recommend that you be renovating.That said, if you renovate the wet area without removing the steel pipe, the failure of the pipe may cause you to have to re-renovate the wet area again at great cost!Cracks/moves in any home wall movement are hard to control.In most cases, cracks are caused by changes in soil moisture levels around the base, although trees can also cause significant movement.If the window crossing is recessed, or the foundation/wall drops, there may be horizontal cracks in the wall.Diagonal cracks radiating from the window or door head are the most common forms of cracks.If the Foundation rotates (drops) on one side, a transverse moving crack may occur under the shear load.Due to the dry climate in Adelaide, the cracking of houses related to shrinkage has caused many problems.This leads to foundation settlement (Foundation descent) and cracks in all building components.Roof frame failure the first type of failure is for old-fashioned roofs without pur bars and/or pillars.In this case, the failure is usually due to the frame being unable to withstand constant load from the weight of the roof tile.It is usually seen that the frame is seriously sunken and divided, and repair in this case may need to be carried out.If the roof frame hangs down due to the weight of the roof tile and the wood frame does not split or show any signs of pressure, we recommend that you closely monitor the roof frame.In the second example, the author saw that the wood around the defective steel nail Truss manufactured in the 1970s S was severely split.In some cases, the truss cannot withstand the roof load and bend.The white ant attack property protection company did not investigate white ants during our inspection and we recommend that you hire pest control personnel to do this.White Ant Attack is a very common problem in buildings, where ants eat any form of wood at home.Since the wooden wall frame is carried in the brick wood facing House, this may cause structural failure.Ants usually enter a place close to the ground.An example of the entry point is that a road and bridge is paved on a wet road, allowing ants to enter the wall cavity through the crying hole (I.e.The paving is poured above the wet road on the wall ).The second example is that the garden bed is placed on the wall without any paving, in which case we recommend removing the garden bed and then installing the paving around the house.The following defects are caused by poor workmanship and do not meet the building specifications.-Render the crying hole on the brick wall, which will prevent the discharge of condensate from the cavity.The author saw the fidgety rendering caused by blocked crying holes.-The prominent position of building blocks.The BCA allows tolerances, but in many cases the concrete does not set the plate correctly.Because the wall is not supported, the brick can stand out.-In many cases, plasterboard does not hit the horizontal line by rendering, which may cause moisture and salt on the ground to rise to the wall through the wet process.This can lead to damp walls.-Cement slabs poured on brick houses.In some cases, around the porch board, Builders sometimes place wet passages on a brick track above the base foot and pour the porch board on the first clay brickIn this case, the clay brick is not exposed to moisture and salt on the ground for a long time, which leads to the wear of the brick.This can sometimes be seen in old houses that if there is a lot of friction on the walls, it is difficult to solve this problem.Depending on the situation of the site visit, in this case, sometimes the best option is to top the floor and then re-lay the concrete under the wet pavement.At the end of the day, this is an expensive issue that needs to be corrected.The author saw this in many garages 1980 ago.-Puddle flange not installed properly to wet area.The puddle flange is designed to drain any water between the waterproof film and the floor tile.In some cases, the flange is proud of the floor and the trapped water cannot be discharged into the waste water pipe.In the building on the second floor, this water can bypass the membrane that causes the wood floor to expand, and doors, walls and window frames can be blocked by compression loads.Repair is very expensive if this happens.-Waterproof film shower in my opinion, this is probably the biggest failure mentioned in this article.If the shower leaks, this can cause serious damage to the wood wall frame through wood rot and water damage.In masonry walls, long-term moisture leakage into the surrounding walls can cause wear and rendering of masonry brick walls.In the metal wall frame, serious rust may occur.In the wood wall frame, the long-term leakage of the shower wall can also cause the expansion, desticking and cracking of the wall cladding and wall tiles.In brick-and-stone walls, high humidity can cause the tiles to crack or strip.BCA (building code) requires silicone in the inner corner of the shower, and many turn-over machines will still be grouting in these areas because the grouting is rigid and these areas cause cracking.The BCA also requires an angle to be installed at the wall floor connection of the shower, which in many cases has not yet been installed.Many waterproof films are not properly installed or the materials used are not correct.That is, the asphalt film penetrates into the grouting instead of the liquid film enhanced with polypropylene gauze fabric.Etc.Most houses built before 1988 will have some cladding of cement stone cotton base.Property Protect can only determine this in our premium report based on our opinion.This can only be verified by analyzing samples under a microscope in the laboratory, so any investigation is based only on our opinion and requires laboratory confirmation.Our advanced report did not analyze the samples in the laboratory.If the material is disturbed by grinding, drilling, or cutting, it can be fatal.Places where it can be found in the house include.-Back panel of the Power board-Old floor coveringOuter eaves cladding.-Wet area cladding, etc.D/The remedy for the failure described above is discussed as follows.The edge of the plate moistens this can be easily solved by placing an opaque film between the pavement and the foundation, or directly on the entire depth of the foundation, preventing the water level from being transferred to the platePlastic waterproof film (liquid or paper) is the best remedy.Salt humidity this can be repaired by forming a new wet process (removing bricks and inserting new plastic film) or by performing a chemical injection in the event of a failure of the wet process (siliconeWhere bridges are laid, wet roads should be lowered.If the rendering Bridge is wet, the rendering can be deleted.In this case, a Breacher piece failure usually removes four brick blocks from the wall, the affected rendering, and the original fittings.Then reverse operation with new material.Brick growth cracks this form of cracks can be prevented by forming a control seam on the wall above the doors and windows to allow the brick to expand from long-term moisture absorption.Typically, if these tiles wear out at the number of turns, they should be removed and then replaced with new concrete roof tiles or metal roof coverings.The only way for concrete cancer to repair this situation is to physically remove the affected concrete, fully expose the steel bars of 360 degrees, place the saw cutting, sandblasting steel, zinc cold galvanized high-quality steel, repair mortar instead of concrete with polymer modified shrinkage compensation.In order to prevent contaminants (chloride and carbon dioxide) from entering concrete, a layer of paint (acrylic resin) should be applied to prevent water and pollutants from entering.This is applied after the repair.Once the trees cause minor damage to the house, it is often not feasible to carry out major repairs from a financial point of view.This can happen in some cases, but this is rare.If the wall has fallen off from the soil shrinkage, the most common rectification is under the Foundation.This includes digging, supporting, pouring new foundation under existing foundation, and then grouting between new foundation and existing foundation.It\'s expensive to DingTalk.If the trees cannot be removed, a trench about 2 m deep can be dug between the House and the tree, and then lined with a non-permeable root fabric to prevent the roots from growing under the house.If the sink and drain are leaking, the rain will be damaged and they should be repaired or replaced.In most cases, these elements are not lost to the street.If so, the rain should be transferred to the street through the rain pipe.Lack of Paving.The basic element to control cracking in old houses is to keep the soil around the foundation within a stable humidity range.This can be done by installing paving.However, in the summer months, in areas close to the pavement, it is important to continuously water the garden at a fixed time and interval.This keeps the soil close to the pavement moist (preferably using an electronic watering system ).To prevent electrical fires, the old lines should be removed and replaced with the installation of the ground leakage circuit breaker by the new PVC line.In order to check whether the existing pipeline is corroded and leaking the pipeline, the plumber can perform a pressure test on the pipeline or use a CCTV system.In general, any old steel or lead pipe should be removed and replaced with PVC, but this can be expensive because the concrete floor requires a jack hammer to get into the pipe.Cracks on walls usually the best way to control movement is to express the house.This allows it to move by installing a wall control joint above the doors and windows and a sliding joint between the hard plaster and the brick.In order to form a sliding joint to remove the rendering, install the mesh on the bricks and replicators with lime-rich mortar.Lime-rich mortar is used to reduce the cement content, thus reducing the rigidity of rendering with 1 cement, 10 sand and 2 part lime mortar ).With regard to soil shrinkage cracks, some soil engineers in Adelaide encourage water to be injected directly into the soil around the foundation around the outer perimeter of the House (mainly on the edge of the park.This is controlled by a computer to inject water into the soil, keeping the soil within a stable moisture range.In most cases, the roof frame failure is easy to pass through the area that supports the depression or damage, or slapping the sides of the member with new wood, or insert additional props to correct (props are usually from the lower pur bar to the inner wall ).In the case of steel nail failure, the overlapping Wood on both sides of the affected wood connected by bolts can also solve this defect.White Ant faultAnts can prevent access to the House by chemical spray, Ant hat (House tripped) or stainless steel mesh barrier (Termimesh.If existing houses are infected, the houses can spray chemicals or insert bait stations around the outside of the House that are actually used as bait with toxic wood (Sentricon system)Property Protect did not investigate white ants in our pre-purchase check and we recommend that you hire pest control personnel to do this.In each case, the work should be done as required in BCA ie.-The crying hole in the render cuts the render out of weepholes-The brick highlights the Foundation to set the floor correctly.-Render bridge wet route through DPC in render-The concrete slab poured on the brick ensures I.e.The porch board is poured on the edge of the main foundation.-The puddle flange ensures that the flange is flush with the top of the floor.Wood/concrete needs to be re-laid to flush the flange with the floor.-Film to shower make sure the film is installed according to BCA.E/conclusion most of the causes of building failures detailed in this casting study are due to seasonal changes resulting in changes in soil moisture conditions around the foundation.The remedial measures discussed revolve around keeping the soil in a constant state of moisture.The measures discussed include the installation of paving and electronic garden watering systems, the diversion of rain from the house, ensuring that the pipes do not leak, keeping the roots away from the base and enabling them to move.Many of the remaining failures are caused by poor maintenance and or construction techniques.Ie wet pavement (not meeting BCA standards) can cause white ant infections and salt humidity.