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OH, GOOD, IT ALREADY HAS A NEW ROOF…

roof

So you have diligently used our blog entries to guide you in viewing a property. You can see concrete tiles and the estate agent has said‘ Don’t worry,  it has a new roof!’ Why should you be concerned?!  Half of the ‘new roofs’ we inspect at in the Bristol area should have Building Regulations approvals and do not. Two aspects!  First, it’s difficult to sell a property without the correct approvals. Second,  the workmanship may not be acceptable if not approved.

As we know,pre 1950’s roofs in Bristol were usually covered with clay tiles (or slates) which were lighter than concrete.  Now it has a concrete roof  so we know from the planning portal that it is likely to need Building Control approvals.  This will ensure the roof structure is strong enough to support the concrete tiles. Also that Fire (Part B) and Energy Performance (Part L) criteria have also been met.

THE STRUCTURAL ISSUE

If it has been re-covered with concrete in the last say 5 years, then very little time will have elapsed. The building’s lifespan is a lot longer than ours!  And the faults linked with overloading the property’s roof structure can take years to develop. The existing timbers (the rafters and purlins) may be too thin to support the new heavier tiles. If they have been replaced, these may also be inadequate.

The replacement covering should have been constructed with input from a structural engineer. (S)He would have determined the loadings. He would then have checked that the load bearing walls were suitable for the increased loadings.

If the timbers have been replaced, they may have the stress gradings stamped on them. This shows the strength of the actual timbers.  C16 is weaker or C24 is stronger. The trada tables then give allowable spans depending on the centres.

Why does this matter? First the rafters will bow, causing the load(weight) of the roof to be sent at an angle into the walls. However, the load should besent vertically straight down to the foundations. This often leads to cracking around the tops of the walls, commonly known as roof spread.  This can be seriously expensive to repair.

Eventually the roof itself will deflect and the tiles become loose… look at the ridge line carefully!

 

WHY WOULD YOU SPEND SO MUCH MONEY AND NOT HAVE THE WORK APPROVED?

It is not normally the vendor’s fault! Roofing works are very expensive so it is likely that the cheaper quotes were accepted. From the roofing contractor’s  perspective,it does make life easier not to inform Building Control!  Awaiting Building Control inspections can delay payments and hold jobs up. And if the work is not inspected, the contractor would not be held liable for infringements at the time.

It is likely that this missing compliance “paper trail” is only identified when selling the house.It normally comes as quite a shock to the vendor!  Indemnities are often offered by the solicitor but thesemerely indemnify against enforcement action being taken by Planning or Building Control. They do not deal with the quality of the structure in any way.

HOW CAN YOU TELL?

There’s a very quick trade secret ! If the has been recently recovered and has less than 270mm of loft insulation present, then it would not comply and hence we know has most likely not been inspected. Otherwise, ask the vendor about the Building Control sign-off documentation. If that is not present, make sure your surveyor inspects the roof structure thoroughly, which won’t happen in a home-buyer’s report !

Internal Walls

INTERNAL WALLS

Internal walls divide the living space into rooms.  They also give strength and structure to the property. Imagine putting a heavy weight on the top of a very large box – it would normally collapse. If you sub divide the box into four smaller areas and put a load on the top, it is likely to bear a lot more weight before it collapses. Houses are very similar. Large open plan spaces in buildings are often a key selling feature. Unfortunately many such open plan areas were originally sub divided, with internal walls supporting the structure above. If adequate replacement supports have been provided, fine. If not, what is most attractive can also be most costly to rectify.

SOLID WALLS

Have you seen builders tapping walls? This is for two reasons – one to see if surface plaster has blown, the other is to determine if walls are solid or stud. A dull thudding sound often suggests a solid partition. These can be made from lightweight blocks or of old timber frames loosely infilled with bricks. When viewing an older property, look for cracks which could signify movement. If the partition wall is leaning, this may suggest something has moved or bowed over time,  usually the floors above or below.

STUD WALLS

These consist of timber frames which are covered both sides with either plasterboard or lath & plaster,  depending on the age of the partition. Contrary to popular belief, stud walls can become load bearing over time – when buildings settle, weight loading can be transferred onto the timber studs. If the building is timber framed in its construction, they certainly can be load bearing! They may be designed to be structural.

ALTERNATIVE MATERIALS

After the war experimental partitions of various types were used.  Usually this occurred in system build and council houses but some types  have been revived in more modern properties. These can sometimes be identified because their thickness is less than 110mm, sometimes as thin as 50mm.

After the war, Paramount partitions were common in Bristol and in PRC (PreCast Reinforced Concrete) houses. The construction was a plasterboard sandwich with cardboard infill for strength -imagine an eggcartontype of configuration.

Stramit was another interesting one. This time, compacted straw was sandwiched between plasterboard.  These were more common in Gloucestershire. They can be very problematic if leaks happen; we have seen plants growing from internal walls as the result of a leak!

Another system we have seen in Gloucestershire, most recently in a bungalow in Coal Pit Heath, is the “clay pot” or extruded clay brick. These are similar to blocks seen on the Continent and were  mainly used in the 1930’s and 1950’s. However, you are unlikely to be able to identify these on a viewing.

DRY LINING

This is a very quick and easy way to disguise poor plaster or dampness. It is literally gluing a plaster board onto a wall or nailing it onto timber battens again attached to a wall. Where dry lining is present, normally as the inner face of external walls, be wary!  Our YouTube video shows the problem, diagnosed by using thermal imaging.  If a hollow sound is heard when you tap the inside of an external wall, be suspicious.

 

REMOVAL OF PARTITIONS

In our first section about viewing a property, we suggested looking at the floor plans of similar properties nearby.  Trawl the estate agents’ websites!  These can give you an indication of the original layout of the house you are considering. Have walls been removed? If so, they should have been inspected in advance by a competent person (a structural engineer or surveyor) to check whether they are load bearing, structural. Ask the vendor if they removed the wall or whether there is any documentation to support the removal of the wall.

If the wall was load-bearing, supports should have been put in place to carry the weight of the structure above. Sometimes smaller nub walls are left to support steel lintels or there are boxed -in downstand beams. Keep an eye out for these – if they don’t exist, you may need to insert them later. Look for any signs of stress along the line where the partition was located, or where the beam is built into the wall. Cracks or failing plaster would be probable indicators.

 

Ceilings

Ceilings

Ceilings are made from a variety of materials and each has different associated problems!

Did you read our blog on inspecting lofts and venture into the loft space (wearing a PP3 mask)? If so, you might be able to lift the insulation and see the type of ceiling material below.

Lath & plaster

Lath & plaster ceilings were used extensively pre 1940. They comprise wooden laths coated with various layers and thicknesses of plaster.  The plaster may contain ash, horse hair and lime.

While working for many leading insurance companies, we have inspected countless collapsed lath& plaster type ceilings.Lath & plaster can and will eventually fail. It happens in the most expensive houses which have decorative cornices that run into thousands of pounds to replace in a single room. It also happens in pre 1930 council houses.  Famously, the ceiling collapse at the Apollo Theatre in London in 2013 injured over 70 people. Such ceilings are seldom used now except in restoration work in listed buildings.

These ceilings are very thick,  normally around 20mm. The tell-tale signs of failure are cracking, an undulating surface and sagging. Finishes such as lining paper tend to mask such cracks but the undulations are easy to see.   Sagging suggests that the plaster has detached from the wooden laths above.  The cracking is not inregular, straight lines -it is normally diagonal and irregular.

Removing such ceilings is a very dirty job!  And it is a real challenge to save any ornate cornices running around the perimeter of the room. This dusty job is often expensive as few want to undertake this work.

Sometimes you can deal with lath & plaster ceilings by underboarding them. Underboarding is screwing a layer of plasterboard beneath the lath & plaster to support it. This is an inexpensive repair but will lower the ceiling height and you will lose any cornicing.

Hardboard

Occasionally in the 1950’s and 60’s, ceilings were constructed from thin sheets of hardboard, ie reconstituted timber. It is normally fairly easy to spot these from underneath, as they have tape over the joints of the boards. This gives the ceiling a grid like type of pattern!

Plasterboard

Since the 1940’s, ceilings have been constructed of uniform boards of gypsum known as plasterboard. These boards have a long service life.In the early days, when plasterboard was first used, the joints were not taped with a netting scrim. Hence minor thermal movements and stress cause straight line cracking, sometimes at right angles.  When this is the case, the joints can be taped  over and the ceiling skimmed. Sometimes nail pops are evident. As long as these are repaired properly (not just covered in filler) they are unlikely to re-appear.

Polystyrene tiles

These were most popular in the 1970’s. They were often used to disguise cracking or damaged ceilings. However, they are a fire hazard as they were not intumescent .  If they catch fire, they can rain molten polystyrene,  a scary image! These should be removed as soon as practicable. While removing the tiles is fairly easy, the plaster beneath will probably be damaged as a result. The spots of glue are also very hard to remove. So allow costs for the skimming often required after removal.

Timber cladding

Timber cladding was another old favourite. These are strips of tongue-and-groove wood and hence are flammable. So they can pose a risk, especially if they are used in a Kitchen. The cladding is not fixed direct to the ceiling; it is often nailed to timber battens which are screwed through the ceiling.  Removing  these will disrupting the finish beneath. Hence you should only undertake this if you are willing to plasterboard and skim the ceiling beneath.

Artex

Artex has been used since the 1970’s, an applied finish with various patterns from stipple to swirl. It was sometimes used on plasterboard instead of a skim, so the characteristic straight line cracks, often with right angles, are very common. Patching Artex satisfactorily  is very difficult and the repairs always seem to be obvious.  Hence when a section is damaged, it is often better to simply skim over the entire ceiling.  However, Artex applied prior to 2000 can sometimes contain traces of asbestos so scraping off the more pointy bits can be hazardous. If such ceilings appear damaged, then it is always best to have tested  it prior to purchase, because  removal of a medium size asbestos-containing ceiling costs around £800.00. And you will still have to replace the ceiling!

Windows and Doors

domestic surveys

Windows and Doors

Windows form a large part of a building and give much of its character! They let in light but they are vulnerable to breakage, accidentally or deliberately. They can usually be opened for fresh air but  can be a security risk. Hence they need to be lockable with a key, to be “approved” by insurance companies. They can also allow heat to escape from the building.

On a viewing, you can easily see whether window locks are present . Again, doors need to be provided with locks that are approved to a BS standard.

Window Frames

The simplest test to tell whether  new frames are required?  Open and close the windows in every room whilst you are viewing. This will take minutes to perform but will indicate the likelihood of a bill for replacement – from £400 per window depending on the size. Yes, even on newer builds – as one minute into this video of our surveys in Bradley Stoke shows! https://youtu.be/1FENY2nJ24Y

There are many shapes and sizes of window, in a variety of materials. Genuine Georgian windows had small panes because glass was difficult to make. The Victorians found new methods of firing glass and so large panes, often in sash windows, became fashionable.

Wooden Frames

Into the 1960s, window frames were made of wood.Older timber frames do offer good thermal performance and can give a long service life, assuming careful maintenance has been carried out. However, they are prone to decay. Sometimes decay is visible as rotting wood. Sometimes fillers have been used. Don’t be afraid of gently prodding, to test the timbers. The filler often looks smoother than the surrounding timber.

Metal Frames

In the 1960’s, steel window frames were sometimes installed, often known as Crittall after the manufacturer. These are normally single glazed with very thin frames. Use a magnet to tell if the frames are steel.  These frames perform very badly thermally and normally have a good coating of mould to show that. These should be replaced.

Aluminium frames were used in the 1980’s. These are lightweight and do not rust. They may have a small brown-coloured layer sandwiched in their construction.  This acts as a thermal break to prevent condensation. If this is not present, replacement is certainly necessary.

As this older double glazing was a lot thinner,  replacement is normally required anyway as it is not feasible to upgrade the glass.

UPVC Frames

The early forms of UPVC were often single chamber or extruded solid plastic,hence  older UPVC windows often do not perform well thermally. Newer UPVC windows have multiple extruded chambers. These act as thermal pockets to make sure that they insulate the interior from the outside world. Combined with e-coatings, this gives one of the best performing arrangements available for the cost.The viable life of UPVC window frames is generally reckoned as 25 years.

Since 2002, new window installations should be “self-certified” by FENSA or CERTAS or in some instances Building Control will sign them off.

Ask the vendor or agent when the windows were last replaced.  Are there any guarantees? If 2003 or later, ask if the relevant certifying  documentation is present.

Glass

Single glazing is simply a single pane of glass.If this is the case, it usually indicates considerable age of a window installation. They allow a large amount of heat to leave the building and sums for replacing them should be budgeted. The reduction in heating bills should eventually pay for this alone!  Large panes of glass can also be dangerous if unmarked.

Depending on the age of the installation, double glazing may be e-coated and toughened.  We use some very special laser equipment to determine if this is the case,as can be seen on this link https://youtu.be/3fsDmGnaJjY . You will not be able to do this yourself, so look for the basics. Is there moisture (often looking like raindrops) in between the double glazed panes? If so, the seal to the double glazing has blown. These can seldom be repaired effectively and replacement is then required. This seal failure can often be as a result of pressure from the masonry, so look around these areas for cracks or distortion of the walls.

Doors

Again, doors may be timber, metal or UPVC, with or without glazed panes. The frames can warp, the locks can be ineffective. The hinges can sag. Replacement UPVC doors can cost upwards of £500, much more for French doors or bi-fold doors.  So do make sure you check them by opening and closing them.

While antique glass in doors, particularly entrances and hallways, is very attractive, it can be a safety hazard. It is unlikely to be toughened so is easily damaged by impact. If you have small children, do bear this in mind!