12 - Building Pathology

Question 1

Q. What are the typical building defects?

Answer 1

A. Penetrating damp. Rising damp. Condensation. Fungal and insect attack. Movement and cracking due to subsidence, settlement or heave. Cold bridging. Cavity wall tie failure. Failure to flat roof covering such as puncture damage to single ply roofing.

Question 2

Q. Explain the different types of cracking you might see on a two-residential building?

Answer 2

A. Subsidence, settlement and heave.

Question 3

Q. When investigating structural cracking to brickwork in residential/low rise property what recognised standards would you refer to assist in classifying the cracking?

Answer 3

A. BRE Digest 251. It provides classification of visible damage to walls and category of damage 0-5, 0 = hairline cracks and 5 = structural damage which requires major repairs.

Question 4

Q. What are the limitations of using a borescope to inspect the cavity of a 1960/1970s domestic dwelling?

Answer 4

Their grave disadvantage is that their viewing is effectively limited to a straight line (rigid borescope).
Also the viewing is subject to the width of the cavity, the space in the cavity needs to allow for the borescope to enter enough to get a proper viewing.

Question 5

Q. Are there any limitations with the use of a damp meter?

Answer 5

A. Need to be aware of the material its being used on i.e. behind the plaster if there is black ash mortar contains carbon which is highly conductive and triggers elevated moisture readings on the meter.

Question 6

Can you expand on BRE 251 ? What are the crack categories ? What are common causes of cracking ?

Answer 6

I have read bre digest 251 assessment of damage in low rise buildings. This defines cracks and assessment of cracking from level 0 a hairline cracking less than 0.1mm up to structural damage cracks greater than 25mm.

 Level 0-5 from bRE digest 251. 
 0 - Hairline crack less than 0.1mm
 1 - fine crack - up to 1mm
 2 - up to 5mm
 3 - 5-15mm
 4 - extensive damage - 15-25mm
 5 - 25mm+ structural damage

Question 7

Can you expand don what your local building stock is ?

Answer 7

Predominantly Victorian redisnetial buildings

Question 8

What is wall tie failure and how would you identify it ?

Answer 8

IDENTIFICATION — Horizontal cracking in every 5 or so brick course or in render. It’s the corrosion of old steel ties such as large fishtail. The corrosion increases the steel up to 4 times leading to the cracking.
REMEDY — use borescope to determine the defect is wall tie failure. Locate wall ties and isolate or removed to ensure no further damage. Install replacement stainless steel mechanical fixed ties secured with an epoxy resin if required

Question 9

What is rot and how would you identify it ?

Answer 9

Dry Rot – Wood shrinks and splits into cuboidal cracks. Wood is light in weight and crumbles under fingers. Usually mycelium on the surface which is grey when wet and yellow/purple when dry. Fruiting body usually brown/red in colour. Indoors only.
Wet Rot – Wood shrinks and splits. Wood darkens. Mycelium grows on surface which can be white, brown, green or amber in colour. Fruiting bodies can be different colours and occurs internally or externally.

Question 10

What did you learn from your PCA Wood destroying insects CPD ?

Answer 10

The investigation, types of insects and remedial actions

Question 11

Can you expand on what trada tables are please ?

Answer 11

TRADA’s Span tables have been in existence for decades now, helping designer and builders quickly look up the right sized softwood members for domestic projects.

In 1991 the Span tables were paid for by government and were included within the Building Regulations.

Question 12

Pethfoot- why did you advise the client that further opening up works would be required regarding the dry rot ? What is dry rot ? What remedial measures did you introduce ?

Answer 12

o A fungal infestation that can have degradation effect on timber. Active at between 20-35% humidity and 0-26oC, fruiting body a rust colour with cotton wool like strands, reactive to light and can travel / grow up to 1m per year, can move through masonry.

Question 13

What are the stages of dry rot ?

Answer 13

Spore
Hyphae
Mycelium
Fruiting Body

Question 14

What are the ideal temp and humid for dry rot ?

Answer 14

20-35 % humidity and 0-26oc

Question 15

Pethfoot - What were the remedial actions for the dry rot ?

Answer 15

Remove compete timber, treat with fungicide (probor 10) rapid drying out of area, introduced of ventilation and reinstall new floor structure

Question 16

Pethoof t- How did you identify the woodworm was active ?

Answer 16

Fresh dusting or frassing under or next to the holes;
You can see light coloured wood in the holes, which have sharp edges;
Edges of wooden beams and joists are breaking away to reveal fresh, light wood underneath.

Question 17

Pethfoot - How did you ensure the remaining /affected woodworm timbers were suitable to remain ?

Answer 17

They were allr replaced in this scenario

Question 18

Pethfoot - what implications did the listing have on the remedial works ?

Answer 18

Limited the available options, concrete replacement floor was not suitable. We liaised with the conservation officer to this regard

Question 19

What are the different types of common damp in buildings ?

Answer 19

condensation, rising damp and penetrating damp

Question 20

How would you identity between dry and wet rot. ?

Answer 20

Dry rot is the most serious form of fungus decay in a building, spreads onto and destroys much of the timber. On the other hand, the wet rot fungus occurs more frequently but is less serious, the decay is usually detained to where the timber becomes and stays wet.

The Wet rot fungus tends to grow on porous surfaces, for example, timber with a high moisture content of around 50% while for dry rot to grow moisture of around 20% needs to be present. If left untreated wet rot can cause major structural problems as it can lead to weakened timbers.

For moisture content to be suitable for wet rot growth there has to be a source of constant moisture – this could be as a result of defective plumbing or damaged guttering. Wet rot cannot spread through masonry and will cease to grow when the source of moisture is taken away. Due to the parts of the building that tend to have the correct moisture levels, for example, underfloor areas, dry rot can often cause significant damage before the homeowner is aware that there is even a problem with dry rot in the property.

Question 21

What are wood boring insects >

Answer 21

A wood boring insect is a common term that covers many species of beetles that as larvae eat and destroy timbers.

Wood boring insects are usually found in areas within a property that are poorly ventilated with a high humidity such as for example a sub floor crawl space. This is usually because these conditions become perfect for the larvae to hibernate and transform into a woodworm beetle.

Question 22

What are the treatment options ?

Answer 22

Treatment and removal of affected timbers

Question 23

How do you use a protimeter and what are the limitations ?

Answer 23

Calibrated for timber, used to verify visual inspection cannot be relied upon.

Question 24

What is a borescope and how do you use it ?

Answer 24

Camera to inspect, normally required to make hole to view iot a cavity as ane example

Question 25

What is limecrete ?

Answer 25

Limecrete is a mix of natural hydraulic lime (NHL5) and sharp sand. Sometimes glass fibres are mixed in to give a more durable surface.

Question 26

267 Jesmond road, at what intervals did you inspect ?

Answer 26

Every 3 months

Question 27

What is concrete carbonation ?

Answer 27

Concrete carbonation is the result of an electrochemical reaction between carbon dioxide, moisture and calcium hydroxide that is present in cement, producing calcium carbonate. Calcium carbonate lowers the alkalinity of concrete from pH12 – 13 to around pH9. This hardens the concrete and increases its compressive strength, but at this reduced pH level the protective passivation layer surrounding the reinforcing steel begins breaks down, leaving the steel vulnerable to corrosion. Rust (Iron oxide) has up to 6 times larger volume than the original steel, so as the steel reinforcements rust, the expansion causes the concrete to crack and spall.

Question 28

What is ASR ?

Answer 28

Most common alkali-aggregate reaction. Concrete is highly alkaline. Water within the pores will also be alkaline. The water can react with silica in the aggregate which produces a gel which expands and causes the concrete to crack. Identified by cracking that is bordered by a colourless gel which leads to spalling. Further testing can be carried out in labs to confirm. For it to occur, it needs silica in the aggregate, moisture and high alkalinity. Remedies include removing the cause of moisture, remove damaged concrete. Introduce secondary reinforcement if needed.

Question 29

Can you give me four examples of wood boring insects ?

Answer 29

COMMON FURNITURE BEETLE (WOODWORM) 3-5m long, dull brown Lines of pits on wings Found on or around damaged timber LATE MARCH – EARLY AUGUST (particularly warm weather. Softwood, European hardwoods 1-2mm dia. Circular flight holes Flight holes random orientation, mainly in direction of grain. Bore dust, cream coloured, lemon shaped pellets. Life cycle 2-5 years LONG HORN BEETLE Adult 10-12mm, black or dull brown. Sapwood or softwoods particularly roof timbers. South-west of London mainly surrey. Flight holes, few large oval, 6-10mm largest dimension. JULY to OCTOBER Cream coloured, sausage shaped. ``` DEATHWATCH 6-9mm long, chocolate brown MARCH to JUNE Bore dust, disc shaped cream pellets Flight holes circular 3mm diameter Mostly oak and elm (hardwoods) ``` WEEVIL 3-5mm long, brownish black. Distinctive long snout. All year around. Flight holes, small ragged, 1mm diameter. Decayed softwood and hardwoods in damp conditions. Mostly found in below ground conditions.

Question 30

Can you give me a examples of deleterious materials ?

Answer 30

``` Asbestos Calcium chlorides Calcium silicate bricks CFC’s Formaldehyde Hair plaster HAC (High Alumina Cement) Hollow clay pot floors Lead Nickel sulphides ```

Question 31

What isa deleterious material ?

Answer 31

The term 'deleterious materials' is a broad one, encompassing not only materials that are dangerous to health or which are the causes of failures in buildings, but increasingly, materials which are environmentally damaging

Question 32

Why did you carry out concrete testing? What is sulphate attack?

Answer 32

Carbonation occurs when the alkaline elements of the concrete react with carbon dioxide creating calcium carbonate which lowers the PH level of the concrete which reduces the passivity. If there is inadequate coverage, the carbon dioxide can react with the protective coating on the steel and corrode it. Levels of carbonation impacted by compaction, temperature, humidity, carbon dioxide levels. Identify by carrying out an onsite test that will change colour when it comes into contact with high alkaline concrete. It is remedied by removing the delaminated concrete, cleaning the re-bar and patching the concrete.

Question 33

Did you refer to any standards for your design?

Answer 33

Approved Doc M, BS 8300 - design of an accessible and inclusive built environment

Question 34

What roof covering did you recommend with option C, was it felt? How would you monitor the construction or the works on site?

Answer 34

Single ply membrane

Question 35

Were any beams used for support where you removed the walls?

Answer 35

yes, designed by structural engineer, steel.

Question 36

Which other parts of the building regs did you refer to for your designs?

Answer 36

Part M, L, A, F

Question 37

Did you check the condition of the timber joists of the garage?

Answer 37

Yes, and reviewed the sizes based on current trada tables.

Question 38

How did you inspect the roof covering to the garage?

Answer 38

Ladders and camera pole

Question 39

What materials can wall ties be made of ?

Answer 39

Iron, steel, stainless steel

Question 40

Difference between wet and dry rot ?

Answer 40

Dry rot can penetrate masonry, different humidity, One of the main differences between wet rot and dry rot is that wet rot needs a higher moisture content to grow. Wet rot fungus likes to grow on timber with a high moisture content of around 50% and above while for dry rot to grow it will germinate at a lower timber moisture content of around 20% to 30%.

Question 41

Why is dry rot seen to be more problematic than wet rot ?

Answer 41

Can penetrate masonry

Question 42

Where would you seek guidance regarding wall tie failure ?

Answer 42

Approved Document A for modern buildings | BRE 401

Question 43

What are the spacings for wall ties ?

Answer 43

Vertical 450mm or every 6-8 courses and horizontal 900mm. See Approved doc A Table 5 for for information. It shows tie length and cavity width.

Question 44

What indicators would you look out for if you suspect dry rot?

Answer 44

Dry Rot – Wood shrinks and splits into cuboidal cracks. Wood is light in weight and crumbles under fingers. Usually mycelium on the surface which is grey when wet and yellow/purple when dry. Fruiting body usually brown/red in colour. Indoors only.

Question 45

Talk me through why you recommended the use of limecrete

Answer 45

Breathability can be important when we consider the floors in old buildings, as they often consist of stone floors laid directly on the earth. In its original situation any moisture below the floor could rise to the floor surface to evaporate away with no detriment. If we then install a concrete insulated floor with a dampproof membrane (DPM), any moisture below the floor will continue to rise and, as the floor is now impermeable, may get pushed to the walls where it could appear as damp spots. It is this that gives rise to the idea of a breathable floor and where limecrete comes in. Limecrete is a mix of natural hydraulic lime (NHL5) and sharp sand. Sometimes glass fibres are mixed in to give a more durable surface.

Question 46

How would you advise the client on a like for like replacement of a timber floor structure affected by dry rot, talk me through the steps.

Answer 46

Consider the affected area Remove affected timbers introduction additional ventilation rapidly dry out the area trat area with a pesticide - probor10 replaced timber if splicing go 500mm past affected areas protect joist ends form moisture ingress

Question 47

Why is dry rot commonly referred to being more problematic than wet rot?

Answer 47

As it can pass through masonry.

Question 48

What typical building defects might you expect to see on a 1960s residential property?

Answer 48

``` Wood wall slabs snapped headers Stone defects sulphate attack in concrete or chimney stack damp penetration timber attacks lead paint asbestos shallow foundations to bays - differential movement ```

Question 49

Explain the different types of cracking you might expect to see on a 2-storey residential property.

Answer 49

Regular Horizontal cracking at regular intervals - wall tie failure Stepped or diagonal cracking - Movement, location dependant Horizontal cracking - Differential movement Cracking larger at top than bottom - Subsidence 0 - Hairline cracks: Less than 0.1 mm in width. No repair action required. 1 - Fine cracks: Up to 1 mm in width. Generally restricted to internal wall finishes. Easily treated using normal decoration. 2 - Cracks easily filled: Up to 5 mm in width. Not necessarily visible externally, but doors and windows may require adjusting to prevent sticking. Can be masked by suitable linings. 3 - Cracks that require opening up: Widths of 5-15 mm. Weather-tightness and service pipes may be affected. External brickwork may need repointing or, in some cases, to be replaced. 4 - Extensive damage: Widths of 15-25 mm. Windows and door frames become distorted, walls lean or bulge noticeably. Requires breaking-out and replacement of wall sections. 5 – Structural damage: Widths greater than 25 mm. Beams lose their bearing, walls require shoring, and the structure is generally unstable. May require major repair works.

Question 50

Where a property is suffering from subsidence, what type of cracking might you expect to see?

Answer 50

Vertical, larger at the top than the bottom

Question 51

When investigating structural cracking to brickwork in residential/low rise property what recognised standards would you refer to assist in classifying the cracking?

Answer 51

BRE Digest 251 - Assessment of damage in low-rise budlings - This defined the inspection and cracking sizes to reference

Question 52

When investigating structural cracking to brickwork caused by adjacent trees what recognised standards would you refer to assist in assessing the risk posed by the trees present?

Answer 52

BRE Digest 298 - Low-rise building foundations - the influence of trees in clay soil

Question 53

Give some examples of high-water demand trees.

Answer 53

``` Elm Oak Willow Poplar Hawthorn - NHBC ```

Question 54

What do you understand by the phrase “tree root moisture extraction”?

Answer 54

The removal of moisture form the ground via the tree routes

Question 55

What are the limitations of using a borescope to inspect the cavity of a 1960/1907s domestic dwelling?

Answer 55

You can only see a limited inspection, if the vanity has been filled your inspection will be poor

Question 56

What alternative methods of inspection could you use?

Answer 56

Inspecti the vanity at opening or from the roof eaves dependant on construction

Question 57

What methods of remedial work are available to deal with cavity wall tie failure?

Answer 57

Replacement and or removal. Replacement via remedial replacement resin set wall ties installed into the brick centre Can also sleeve existing wall tie to limit further expansion Treat existing wall ties with anti corrosion paint

Question 58

If a property was suffering from dry rot, what might you expect to see?

Answer 58

Dependant on the outbreak, a lack of ventilation. You would see damage or cuboidal cracking to the affected timber if visible then Spores the dust presence of the rot Hyphae 0 fine what strands Mycelium - a collection of mass of hyphae fruiting body - mushroom like appearance 0 dark red - releases the spores and the cycle starts again

Question 59

What types of wood boring inspect might you expect to find in domestic dwellings in the UK?

Answer 59

Common Furniture Beetle. House Longhorn Beetle. Deathwatch Beetle. Wood Boring Weevil.

Question 60

Are there any limitations with the use of a damp meter?

Answer 60

Design and calibrated for timber, foil backed plaster board will give inaccurate readings, it should eb used to back up visual identification

Question 61

Explain how you would test a masonry wall for the presence of damp and how you would differentiate between the different types of damp likely to be present

Answer 61

I could use a protimeter or a speed carbide test to seek what the moisture contents of the area is. I would consider the location and construction to determine the type of damp

Question 62

How would you identify condensation in a property?

Answer 62

Consider the location and presence of damp, normally is low air flow/changes area, behind furniture, corners of room, near or adjacent to bathrooms and kitchens. Normally black spots.

Question 63

Give some examples of the likely causes of penetrating damp.

Answer 63

Slipped slates, blocked gutters, failed tanking systems.

Question 64

What is nail fatigue?

Answer 64

That as a roof ages the fixings which are often nails start to fail resulting in tile or slate slippage especially in windy weather conditions.

Question 65

What is concrete carbonation?

Answer 65

Carbonation occurs when the alkaline elements of the concrete react with carbon dioxide creating calcium carbonate which lowers the PH level of the concrete which reduces the passivity. If there is inadequate coverage, the carbon dioxide can react with the protective coating on the steel and corrode it. Levels of carbonation impacted by compaction, temperature, humidity, carbon dioxide levels. Identify by carrying out an onsite test that will change colour when it comes into contact with high alkaline concrete. It is remedied by removing the delaminated concrete, cleaning the re-bar and patching the concrete.

Question 66

Explain the cause of concrete carbonation.

Answer 66

The carbon dioxide being absorbed into the concrete to cause calcium carbonate which lowers the concrete ph., which can affect the protective coating on the steel reinforcement.

Question 67

Explain the testing procedure when testing for concrete carbonation.

Answer 67

The extent and depth can be confirmed using a phenolphthalein solution Phenolphthalein solution reacts with the concrete – changes to pink if uncarbonated concrete and remains colourless on carbonated concrete Carbonation depth is assessed using a solution of phenolphthalein indicator that appears pink in contact with alkaline concrete with pH values in excess of 9 and colourless at lower levels of pH The test is most commonly carried out by spraying the indicator on freshly exposed surfaces of concrete broken from the structure or on split cores Alternatively, the powder from drill holes can be sprayed or allowed to fall on indicator-impregnated paper or a core sample and the solution sprayed on Cover meter can detect reinforcement positions, cover depth and bar diameters Structural assessment may be required

Question 68

What is a deleterious material? – give some examples.

Answer 68

The term 'deleterious materials' is a broad one, encompassing not only materials that are dangerous to health or which are the causes of failures in buildings, but increasingly, materials which are environmentally damaging. ``` Asbestos Calcium chlorides Calcium silicate bricks CFC’s Formaldehyde Hair plaster HAC (High Alumina Cement) Hollow clay pot floors Lead Nickel sulphides ```

Question 69

What are the symptoms you might expect to find if a concrete floor was suffering from sulphate attack?

Answer 69

Cracking

Question 70

Explain why sulphates in hardcore can result in sulphate attack.

Answer 70

As they are not protected with a DPM when they comes into contact with a water source they expand and can transfer this up into the slab above

Question 71

Why is sulphate attack unlikely to be present in a property built in the 1990s?

Answer 71

As there will have been a more modern construction detail including a DPM and higher quality hardcore.

Question 72

What current challenges is Covid and/or Brexit bringing to Building Pathology?

Answer 72

Inspection, sourcing of material labour etc

Question 73

Q. what was the construction at Waterton House?

Answer 73

A. cavity wall construction, on trench foundations with timber roof structure.

Question 74

Q. What caused the low diagonal cracking?

Answer 74

A. it was due to subsidence. The gulley didn’t have a cover and was filled with silt and debris. Through opening up works it was identified the pipe underneath the ground was cracked allowing excess water to seep into the ground under the foundations and wash away the sub-soil. I advised the client the damaged pipe would need to be replaced first to allow the water to flow through properly, then to carry out crack-stitching to the cracked mortar joints. Steps: grind out the mortar, install grout then the helical steel bars, then to re-point the joints.

Question 75

Q. what were the main defects at this building? Rutland Mills.

Answer 75

A. during my survey I identified cut edge corrosion to the metal profile roof and due to the ongoing long term leaks the timber roof structure had suffered from wet rot causing the roof timbers to become weak. I reported to the client that spliced repairs will be required to the roof timbers.

Question 76

Q. what age was the building what typical defects would you expect to find?

Answer 76

TBC

Question 77

Q. what is cut edge corrosion?

Answer 77

A. steel edge sheets are exposed to oxygen which are prone to corrosion which is exacerbated by water pollutants. Consequently, the factory coating can peel off from these edges causing them to corrode. Tough cut edge corrosion usually begins around edges it gathers speed through capillary water action and can spread.

Question 78

Q. due to the leak that compromised the structure, how did you conduct your survey?

Answer 78

TBC

Question 79

Explain how you carried out your inspection.

Answer 79

I inspected the property both externally and internally to understand the scale and construction. I then inspect the adjacent area to the report defects and inspect the sub floor via a access hatch to review the sub floor arrangements.

Question 80

What was the significance of the rippled wallpaper?

Answer 80

It indicated a area of movement since the last decoration and the remaining decoration was to a high standard.

Question 81

What further investigation was necessary/carried out/recommended? Explain how you determined the existing joists were undersized.

Answer 81

I references the existing joists on the current trada tables to confirm by todays standards they were undersized. Further investigations ?

Question 82

Explain how you determined the existing joists were undersized.

Answer 82

I references the existing joists on the current trada tables to confirm by todays standards they were undersized. Further investigations ?

Question 83

Describe the remedial work you recommended to resolve the problem.

Answer 83

The installation of intermediate support to reduce the unsupported span of the floor joists.

Question 84

What did you recommend to rectify the bowed joists?

Answer 84

Assessment of each and potential replacement

Question 85

What defects did you see that led you to suspect sulphate attack?

Answer 85

Cracking of the concrete oversight

Question 86

What testing is available to confirm your diagnosis?

Answer 86

Tsmapling and analysis of the concrete oversight for the presence of sulphates.

Question 87

What are the limitations of testing for total sulphate content?

Answer 87

Costs are high and not guarantee that it will not happen in the future.

Question 88

What alternative types of testing are available?

Answer 88

????

Question 89

Explain how you confirmed your diagnosis in this case.

Answer 89

By the testing method and the cracking.

Question 90

What was your advice/recommendations in respect of the remedial work necessary to rectify the defect?

Answer 90

To remove and the replace the floor in its entirety, removing the sulphate and installing a DPM.

Question 91

How did you/or would you assess the sub-floor structure for the presence of damp?

Answer 91

protimeter or speedy carbide test

Question 92

How would you investigate for the presence of a DPM in the floor structure?

Answer 92

look at the perimeter for evidence other destructive testing

Question 93

What do you understand by the phrase “plaster wicking’ in respect to low level damp in masonry walls?

Answer 93

The same term used for rising damp - The unwanted ingress of water that rising through capillary action

Question 94

what is condensation?

Answer 94

A. moisture in the air (water vapour) is held in high temperature air and when it comes into contact with a cold surface it is cooled, and the excess vapour condenses (dew point)

Question 95

Q. how did you conduct the use of a moisture meter?

Answer 95

A. I used the moisture meter in the front basement timber only to take readings of the timber floor joists. The floor joists were showing low moisture readings. There were no signs of insect attack. The rear basement was where the dry rot had occurred and this was identified when the wall covering was stripped off, it was growing around the timber studs. I advised the client that all timbers (i.e. door frames and architraves etc) will need to be removed off site and remove nearby timbers within 0.5 meters of the last outbreak of the dry rot. I also advised that fungicidal treatment would need to be applied to all masonry and all good timbers.

Question 96

Q. what are the limitations of using a moisture meter?

Answer 96

Foil backed plaster, black ash mortar

Question 97

Q. what was the construction of the building?

Answer 97

A. early 1900’s building with solid wall construction, and timber roof structure.

Question 98

What clues were present to lead you to suspect the presence of dry rot?

Answer 98

The presence of mycelium, fruiting body and the damage to the timber suspended floor.

Question 99

Outline the key differences between the characteristics of brown rots and white rots.

Answer 99

Dry Rot Cuboidal cracking Moisture content around 25% Timber can crumble Wet rot soft and spongy timber higher moisture contents - 30% plus

Question 100

Outline the key characteristics which are used to diagnose dry rot.

Answer 100

moisture contents | Visual identification

Question 101

What is your opinion of the use of chemicals used to treat timber and brickwork when eradicating dry rot?

Answer 101

Can be used however the source of moisture should be eradicated and the drying out and rapid heating of the space should eb encouraged]

Question 102

What do you understand by the term environmental control in respect of treating dry rot?

Answer 102

Using the weather, wind, etc to assist in removing the rot.

Question 103

How did you determine the amount of opening-up required?

Answer 103

Via an initial inspection from removing a floor board

Question 104

What advice did you give in respect of remedial works?

Answer 104

Full removal of the flooring in the affected rooms due to widespread deuteriation of the timber floor

Question 105

What advice did you give in terms of contractor’s guarantees associated with the remedial work?

Answer 105

As there was full replacement the works fell under a larger package of works at the property.

Question 106

Explain your advice in respect of the structural movement?

Answer 106

I advised the initial period of monitoring to determine of the movement was historic or continuing

Question 107

Describe the cracking in terms of size, direction, and general appearance.

Answer 107

Vertical - approx. 1mm in width - Level 1 (BRE 251) consistent in width.

Question 108

What was the ultimate cause of the structural movement?

Answer 108

Historic

Question 109

What advice did you give in terms of remedial work?

Answer 109

Re sealing of the adjacent timber structure and door framc to ensure water tight

Question 110

What was the purpose of monitoring the situation for 12 months? Was this long enough to establish if the movement was historical and had ceased?

Answer 110

To seek the seasonal changes, however consideration was given to a longer period of time if the winter was warm and the summer cool.

Question 111

What is hardcore?

Answer 111

Hardcore is fill material used in building construction to raise ground levels and provide a dry, firm and level base on which to cast a concrete ground floor slab or ‘oversite’ concrete beneath suspended floors.