Building Pathology Flashcards
what are the 4 Japanese knotweed treatments?
excavation
mechanical
root barrier
herbicide
Japanese knotweed - what is Excavation Method?
Which involves digging out and removing all knotweed material.
Once the knotweed has been fully excavated The traditional method has been to dispose of it as landfill.
Japanese knotweed - what is Mechanical Method?
This is not an eradication method in itself but involves weakening the rhizome
of the plant by cutting it up into smaller pieces and pulling some of the deeper
rhizomes closer to the surface. This makes the knotweed more susceptible to
other forms of treatment.
Japanese knotweed - what is Herbicide Method?
This involves the regular use of herbicides, usually over a few growing seasons,
to gradually kill off the plant.
Japanese knotweed - what is root barrier method?
Barriers are used to contain knotweed that, for one reason or another, cannot
practically be excavated (e.g. rhizomes that spread across boundaries or are in
close proximity to structures).
what is Japanese knotweed?
Japanese knotweed is a fast-growing and strong clump-forming perennial, with tall, dense annual stems. Stem growth is renewed each year from the stout, deeply-penetrating rhizomes (creeping underground stems).
what does Japanese knotweed look like?
n spring, reddish-purple fleshy shoots emerge from crimson-pink buds at ground level.
in summer, dense stands of tall bamboo-like canes. These canes have characteristic purple flecks, and produce branches from nodes along its length.
Leaves are heart or shovel-shaped and up to 14cm and borne alternately (in a zig zag pattern) along the stems. The stems die back to ground level in winter, but the dry canes remain for several months or longer.
creamy-white flower tassels produced in late summer and early autumn.
whats the problem with knotweed?
Japanese knotweed can sprout from very small sections of rhizomes. Under the provisions made within Schedule 9 of the Wildlife and Countryside Act 1981, it is an offence to cause Japanese knotweed to grow in the wild.
its an invasive plant and can get into your building and structure
whats the law around knotweed and buying and selling?
Since 2013, the seller is required to state whether Japanese knotweed (Fallopia japonica) is present on their property through a TA6 form. The TA6 form asks you to confirm whether your property is affected by Japanese knotweed and, where it is, to provide a management plan for its eradication from a professional company
K-Value
K-value indicates the ability of a material to conduct heat. Materials with low thermal conductivities do not easily allow heat energy to pass through. Normally, you would look for a material with a low K-value to insulate, as this will keep the cool inside your building.
R-Value
R-value refers to a material’s ability to resist heat transfer at a certain thickness. When looking for a material to insulate your building you would generally look for a material with a high R-value, and therefore, one that can resist heat transfer well
U-Value
U-value assesses the rate of heat loss through a given thickness of a building element (roof, wall or floor). Ideally you would want a material which gains a small amount of heat in any given time, so you would want the U-value of a material to be low
Quoin what is it
A quoin is an external cornerstone that is found at the corners of brick or stone buildings. Quoins have been used for many years, but in the beginning, they were just a way to connect the corners of walls to make the right angle.
what is the life cycle of insects
It starts with an adult female depositing her eggs in the wood. The eggs hatch and a small grub-like larva emerges. It’s the beetle larvae that feed on wood, and they may continue eating the wood for several months or, in some cases, up to 20 years depending on the species.
types of woodworm beetles?
- Common Furniture Beetle
- Deathwatch Beetle
- wooodboring Weeviles
- Powder Post Beetle
- House longhorn Beetle
what are indications of insect infestation
- Exit holes in timber
- Presence of frass (bore dust)
- Tunnels within the wood
- Damaged wood
- Actual beetles
How would you determine which beetle you have?
First you would look at the location you are in, and what beetles are common in that area and which ones have never been seen. It’s unlikely to be one which has never been seen. Next you would be looking at the size of the tunnel hole, different size holes are left by different beetles, and then you would also be looking at how bad the damp is, some beetles like it very damp and some only a little bit damp. You would also consider what wood has been attacked as some like soft wood and some hard.
What is the treatment method for insects?
Water based woodworm treatment - This highly effective and odourless solution is sprayed into the timber and will remain in the layers of timber and woodworm flight holes to prevent any future infestations.
Fogging treatment - Rentokil’s unique fogging systems are often used to treat under flooring and floorboards. By lifting one length of floorboard for access, this treatment allows carpets and furniture to be left indoors during the treatment.
Fumigation treatment - ProFume is a specialist fumigation treatment which is exclusive to Rentokil in the UK. The fumigation process is mainly used for our commercial premises and will effectively treat woodworm with no damage to property.
What types of damp are there?
The most common causes of persistent damp in buildings are:
Condensation (surface or interstitial).
Rising damp.
Penetrating damp.
Condensation
Condensation occurs when moist air cools below its dew point, and water condenses. This can occur as surface condensation, but also within the fabric of a building itself, as interstitial condensation.
Rising damp
Rising damp is caused by incorrect placing of, faults to, or the absence of a damp-proof course, and is generally only apparent up to 1 m above ground level because of the limits of capillary action to draw moisture up through porous elements of the building structure.
Penetrating damp
Penetrating damp is moisture that penetrates laterally through the fabric of a building, typically as a result of leaks to pipework, damage to the building fabric which allows water to penetrate, high ground levels, blocked drains, leaky gutters, cracked masonry, broken flashings, etc.
How do you identify damp?
Observation
Manual viewing
Moisture meters
Laboratory techniques
Drilled samples and moisture contents can be subjected to techniques such as a carbide meter, oven drying and soluble salt analysis. These can be used to confirm the results of thermal imaging and thermo hygrometry.
Temperature and humidity measurement
Recording the relative humidity (RH) and temperatures in a series of rooms and outside using half hourly sampling can be an effective way of diagnosing damp.
How do you spot rising damp/ penetrating damp or condensation?
Rising damp usually affects ground level floor rooms/basements. It will travel through porous material such as brickwork or mortar. The signs will include decayed skirting boards/floors, peeling paint and wallpaper. You may also see a white tidal mark left behind from the salts. Rising damp typically has a low height and rarely is above 1.5m.
Penetrating damp is often caused by defects such as gaps in brickwork, window frames, defective roofs ect. You may have brown stained internal walls due to the water getting dirty while travelling through the building materials.
Causes of damp due to condensation
Damp due to condensation is common in poorly ventilated rooms and particularly in rooms with a high moisture content, for example kitchens and bathrooms.
Common sources of water vapour include bathing and cooking. When this moisture is not addressed quickly enough mildew and mould occur.
n the UK problems with condensation are very common between October and March as at these times the walls are much colder than the air inside.
Condensation is often provoked by other forms of damp that result in the external wall being cold.
what does damp due to condensation usually look like?
Damp caused by condensation will appear as black speckled marks or grey growths.
Interstitial condensation can also occur, this is when condensation forms within the wall itself. Buildings with poorly insulated walls are very prone to this. Interstitial condensation causes damage that looks very similar to penetrating damp and often occurs in similar places.
Condensation Remediation?
needs better ventilation. Installing an external extract or installing window vents. You could get a de-humidifier in for the mean time to extract all of the moisture, and then you may need some redecoration perhaps using a lime wash on the walls to try and get some breathability.
What is a foundation?
Foundations are support to the building from below ground level, it spreads the load of a building to the soil.
When you choose foundations, what things would you consider?
The first thing you would consider is the soil composition underneath you, also whether you are on a flood plane, or near the water. What kind of building you are building, if you have columns, the space you have, costs and environment. E.g is there is nearby trees ext.
There’s two types of foundations before we go into the detail of what the foundations are. Do you know what those two types of foundations are?
Deep and shallow foundations
Shallow foundations are used when the load of the building is light to medium. A deep foundation would be when you use piles ect for a heavier construction e.g flats.
The shallow foundations, what types are there?
Strip foundations, Raft foundations and Pad foundations
What is a strip foundation?
A strip foundation is like it’s an excavation and a continuous strip of foundation and then the trench foundation is a variation of that and that’s when the majority of the expiration is full of concrete. The foundation will strip along the load bearing walls.
What is a pad foundation?
A pad foundation is used for columns, to support the load.
What is a slab foundation?
Slab Foundation is what you would use if the ground conditions weren’t great or if settlement was likely so. They also cover the whole structure. Its just one full (slab) of foundation)
What site surveys would you consider when choosing a foundation?
Borehole. You must also do boreholes in more than one place, as your ground conditions may differ. You may also do a topography survey.
What type of deep foundations are there?
I’m so you’ve got piles which are core drilled. They could be either concrete or steel.
If you’re a bit more pushed for space, you would use mini piles.
why would you use deep foundations?
when the ground is soft and a solid bed is not available.
