damaged party wall structure

It is worth checking before starting your project that you get advice well in advance. If you start work without following the correct procedure you have the possibility of ending up with delays and associated increased contract costs, potentially an expensive legal dispute, and if you’ve caused damage, almost certainly a hefty compensation payment to the adjoining building owner.

The Land and Conveyancing Law Reform Act 2009 is designed to help neighbours resolve any boundary wall and party wall disputes about works on or near the party line between two properties if they themselves cannot come to an agreement. The Act allows the building owner to do works following an application to the District Court for a “works order” whilst protecting the rights of the adjoining owner. In some cases works can be carried out without first consulting the adjoining owner.

If you are your neighbour plan to go ahead with any construction on or adjacent to the party wall / boundary wall, always get the opinion of a party wall surveyor to check that your structure will not be damaged and equally importantly that the proposed neighbours structure will not restrict you from building adjacent to the boundary on your own property in the future.

If you are concerned about works your neighbour has carried out which has caused damage, you may need to instruct a surveyor to examine the damage in order to help you complete your claim.

Assuming you do need to appoint a party wall surveyor to act for you, ideally they should have specialist knowledge in this area.

septic tank problems

About Septic Tanks and Secondary Treatment Systems.

HOW SEPTIC TANKS WORK

Septic tanks are designed to allow liquids to flow through the tank and enter a percolation area without causing damage to the environment. Waste waters enter the tank and the flow is reduced through a series of baffles allowing the solids to sink to the bottom. Additionally, smaller particles float to the surface creating a scum. By holding the water in the system, suspended solids are removed and much of the sludge decomposes through natural aerobic and anaerobic processes.

In turn the semi-treated liquid is allowed to exit the tank into the percolation area and beyond.

Emptying Frequency.

There is no hard and fast rule, but for a septic tank to work efficiently the sludge (solids) needs to be removed based on the capacity of the tank and the use it is subjected to. The frequency of “de-sludging” will depend on size of the property and the number of occupants. However, most will require emptying at least once a year are in the case of modern biocycle system or secondary treatment systems according to the manufacturers specificiations.

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Tips in improving efficiency of septic tanks.

• Don’t dispose of: commercial chemicals, medicines, disposable nappies, incontinence pads or hygiene products down the toilet.

• Don’t use large quantities of biological cleaning agents and bleach.

• Don’t hose down the baffles and media areas of the tank. It is important for the bacterial media to remain and restart the biological process.

• Do have the septic tank “de-sludged” regularly.

• Do use biologically friendly products.

Typical Problems and Solutions

Odour

Likely cause, Sludge particles leaving the septic tank and entering the percolation area or sludge has blocked the exit and the tank is overflowing.

Solutions: Have the tank “de-sludged” or emptied.

System backing-up

Likely blockage in the in-let pipe, blockage in the out-let pipe. percolation area blocked.

Solution: Clear in-let and/or out-let pipe. Remove and replace percolation area.

Septic Tank refilling immediately after emptying

Likely, high water table. Ground water enters the tank via the percolation area.

Solution: None. (possible solution is to increase the height of the area were septic tank and percolation area ore located-expensive and not always a solution)

Septic Tank refilling immediately after emptying

Likely, High water table : Tank ruptured allowing ground water to enter the tank.

Solution: Clear and clean tank, inspect, repair or replace.

Differences between septic tanks and biocycle (secondary treatment systems).

A septic tank does not have any movable parts. its basically a two chamber concrete tank that uses anaerobic bacterial action to break down effluent waste.

Biocycle and other secondary treatment systems have movable parts such as maceraters, aerators etc to aerobically break down the effluent and need a source of electric power to operate.

Biocycle / secondary treatment systems have shown to breakdown a higher percentage of solid waste and have safer effluent than septic tanks as the sludge decomposes through a mechanical assisted aerobic and anaerobic process. This can be twice as efficient as a non-mechanical assisted aerobic and anaerobic process in a traditional septic tank.

The requirement to use a septic tank or secondary treatment system is usually dependent on the site conditions, however most Local Authorities (following a site assessment), will now require the use of a treatment system fitted by an approved contractor with appropriate professional indemnity insurance. Always check with your Local Authority before carrying out any renewal works to an existing septic tank.

An occupier of a property can be subject to substantial penalies if their septic tank or secondary treatment system is found to be polluting the environment.

General Information and Running Costs.

The septic tank’s main function is to remove solids from the effluent, allowing a liquid effluent to soak into the soil through the percolation area.

The efficiency of septic tanks can vary significantly, frequent desludging of ineffective septic tanks can prevent anaerobic digestion of waste materials further reducing the

efficiency of septic tanks.

A biocycle system or a secondary treatment system, is a more efficient and effective treatment system that incorporates a septic tank and a submerged aerated filter for secondary treatment within a single tank. The desludging intervals can also extend up to seven and more years according to some manufacturers. These secondary treatment systems will normally require to be serviced by an approved contractor on a yearly basis according to manufacturors specifications

A properly designed and installed secondary treatment system, can be up to twice as efficient as a traditional septic tank system in breaking down waste and discharging a cleaner effluent to the environment.

A secondary treatment system should have all paper work including design and installation assessments, site assessment and planning conditions available for inspection to confirm that it has been installed to standards and complies to planning permission requirements.

Running costs, depending on the type of secondary treatment system in use, a secondary treatment system runs on electricity continuously and would be expected to consume at least as much power as a fridge.

The treatment system will also require to be desludged as per manufacturors spectifications.

There is also an annual service charge for the inspection of the secondary treatment system plus the cost of labour and parts if they need to be replaced or repaired.

Pending Legislation on the Licensing and Regulation of Septic Tanks.

The European Court of Justice has ruled against Ireland for failing to have a proper system of licensing and regulating individual septic tanks.

It is estimated that there are over 400,000 septic tanks in Ireland.

It is accepted that many septic tanks and percolation areas have been constructed in areas not suitable for same and their maintenance is often ignored.

Ireland is required to introduce a scheme to insure that septic tanks and waste water disposal are in compliance with EU Regulations and to maintain compliance into the future.

It is expected that the proposed scheme would include a

i) scrappage remit to facilitate the replacement of inefficient / polluting septic tanks and treatment systems,

ii) an inspection schedule to ensure ongoing maintainance and monitoring of septic tanks,

iii) a licensing system that is renewable

iv) an enforcement element.

Operation of Septic Tank inspection scheme.

Some commentators consider that a system similar to the NCT (National Car Test) would work, in that each property owner would be given a date when an Inspector is to call to their property. The property owner would allow for access to the septic tank including relevant documentation and maintenance records. The costs of the inspection would likely be carried by the property owner.

If the septic tank is found to be working correctly, then a certificate would be issued and remain valid for a limited number of years.

pyrite causing cracks in walls

Pyrite And Your Home

The damage that pyrite can cause is stressful to the home owner and an expensive problem to remedy. The possibility that pyrite may have been used in a small number of homes in a development can have a very negative affect on all property values in that development. The presence of pyrite in the backfill in almost all cases cannot be seen from a visual inspection. Pyrite in backfill can take upwards of 40 years to fully oxidise (swell) and become stable. Removing pyrite is an expensive task which involves supporting the existing first floor structure and roof, removing the existing concrete floor slab, partition walls resting on the floor slab, removal and replacement of all services in the affected area, removing all existing contaminated gravel and then replacing same with proper materials.

Pyrite affected backfill has been used in house construction for possibly up to 20,000 homes in Ireland.

What is pyrite.

Pyrite (FeS2) is a very common mineral. Traces of it can be found in the sedimentary rock (quaries) used to make crushed stone for backfill.

By itself pyrite is not normally a problem, but when you combine it with moisture and oxygen in a confined space it can become a problem.

In the presence of moisture and oxygen, pyrite oxidizes and produces sulphuric acid. The acid reacts with the calcium carbonates found in the crushed stone and swells.

Swelling of the backfill under floor slabs.

If pyrite affected backfill never got wet, or had no access to oxygen, it would remain mostly static.

In the presence of moisture and oxygen, pyrite oxidizes and produces sulfuric acid. This acid reacts with calcium carbonates found in the backfill. The chemical reaction results in the formation of sulphate and gypsum. The gypsum crystallizes and causes the backfill to swell under the concrete floor slab. Over time this chemical reaction will cause the concrete slab to flake and crumble.

This swelling will lift the floor slab and interior structural supports resting on it. Swelling is usually worse if there is a higher concenstration of pyrite in the backfill and the amount of swelling is also determined by the thickness of the backfill.

This is usually a slow process. On average, experience from similar problems in Canada suggests it can take about ten years before any noticible damage is noted.

Frequently Asked Questions about Pyrite.

If I suspect pyrite what evidence do I look for?

Depending on the type of construction, backfill is often placed under concrete floor slabs. The presence of Pyrite in the backfill can result in a section or the entire entire floor slab to lift several centimeters, causing cracks in the slab. Internal and external doors may also stick and/or catch on the floor.

There is also a visual presence of needle-like white crystals mixed with the concrete near the cracks.

Cracks caused by Pyrite can be seen by sections of the floor rising in the corners of rooms or in the form of a cross or a star towards the centre of the floor. These types of cracks can take one to 1 to 10-20 years to appear.

Does sulphation result in concrete slab floor to swell and crumble?

Sulphation will result in the concrete slab swelling and crumbling. It can result in swelling up to 150mm. The moisture under the concrete floor slab rises upward, lifting the sulfuric acid which has resulted by oxidation of the pyrite. When sulfuric acid comes into contact with the underside of the concrete floor slab, the concrete swells from sulphation and starts flaking and crumbling.

The swelling concrete expands. The strip foundations and rising walls may prevent horizontal expansion; so the swelling usually occurs upwards from the centre or corners of the floor slab.

Does pyrite cause damage to foundation walls?

In limited cases, the lateral forces of the swelling backfill will produce cracks in the foundation rising walls around the property.

What age properties are affected?

The majority of properties affected have been built during the celtic tiger years, However some older properties are also affected and occaisionally the defect was not correctly diagnosed.

Is Pyrite a health issue?

The swelling of backfill does not have harmful effects on the health of the occupants of the house, save for the stress it leads too. The vast majority of expert opinion is that the quantities of sulfuric acid are too minute to cause health problems. It is possible that the radon barrier maybe compromised leading to ingress of radon gas into the dwelling.

How quickly will I see the affects of pyrite?

Damage attributable to swelling caused by pyrite can appear very soon after construction is complete. Swelling may occur sooner if oxidation of the backfill has already started during construction. This may happen if the crushed stone has been exposed to a moisture. The speed of reaction will depend on several factors. Pyrite can take between ten to forty years to fully oxidize.

Can I slow down the rate of swelling?

Absence of moisture can reduce the speed of the swelling of pyrite backfill. The process of oxidation cannot be prevented but oxidation over a longer period of time could result in less damage than rapid oxidation. Ground level moisture can be reduced by better surface drainage immediatly outside the exterior walls.

What if I have a long fine crack in my concrete floor?

Most concrete floor slabs will develop drying cracks. This is normal when floors dry out too quickly. As concrete dries, it shrinks. These cracks are most likely not caused by swelling due to the presence of pyrite.

Who should I call if I have a suspected pyrite problem?

Contact your builder or insurance company if your property is covered under an insurance guarantee. Also check with neighbours in your estate to see if anyone is complaining about a similar problem. The testing for the existance of pyrite is evaluated by specialist laboratories which test for pyrite from sample submitted to them and not by a visual inspection.

There are a number of specialist engineers and contracting companies who specialise in pyrite investigation.

What is the main longterm solution to remedy a pyrite problem?

The only longterm solution is an expensive solution which involves substantial building works as follows.

Break and remove the concrete slab floor

Excavate and the backfill and any contaminated subsoil

Replace backfill according to Part D of the Building Regulations.

Pour a new slab.

Existing services, partition walls and first floors would also need to be replaced and supported during this re-instatement.

This work should be undertaken by competent building contractors.

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blocked drain

About Plumbing

Mains water supply and shut off

The mains water supply takes water from the public water system or private well system to the property.

All shut off valves should be turned on and off fully at least twice a year, this will help prevent valves from sticking or seizing.

Interior plumbing line Materials

Interior plumbing line materials should be sufficiently robust and in good condition to adequately carry water to where its required and to discharge waste water to the outside drains.

Water Pressure

The supply piping should be capable of delivering adequate water to the fixtures. The flow of water from a tap / fixture is a relationship between the volume and the pressure. The volume of water coming out of a bath tap is more important then the pressure of the water and conversely the pressure of water coming out of a shower head in more important then the volume of water.

Drainage Flow

The drainage should be capable of discharging the entire supply of water from a fixture and also be capable of draining away the water as fast as the taps deliver it.

Venting

The plumbing system must be adequately vented so water released from a fixture may draw in air to allow a smooth and even drainage flow. The system will attempt to draw in air through other fixtures and siphon the water from their traps if not properly vented.

Fixtures

These are the sinks, bathtubs and toilet fixtures of the plumbing system. These fixtures should be securely braced to walls an floors. Fixtures normally only need to be replaced when damaged, have sharp edges or leak. Scratched and dirty fixtures and taps can provide a breeding ground for bacteria to grow.

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