This chimney has movement through brickwork due to weeds growing through it over many years and also deterioration of render.
Mortar is “Lime Mortar” meaning mainly lime and sand which over time becomes soft and sandy. Reason for using “Lime Mortar” is when old handmade bricks are used, they are usually soft and if the mortar or render is stronger than the handmade brick the mortar can pull the face of the handmade brick. It is important not to use any mortar or render stronger than the brick
Note even the lead flashing is in poor condition.
Works here involves removing existing render and moulds, removing loose brickwork and replacing any deteriorated bricks using lime mortar mix with a little cement.
Running of moulds to original profiles, rendered and new lead flashing to complete full chimney restoration.
For a box gutter to work at its best, it has to have an emergency overflow so that water has somewhere to go in the event of the gutter being blocked or extremely heavy rainfall. If there is not such an overflow, the water will go straight into the roof space and into your building and this can cause a number of problems. Most good box gutters have the emergency overflow however. For further protection, you can also install a gutter guard so that leaves and debris cannot block up the gutters and you also have the advantage of birds, pests and other vermin being unable to enter your roof space. The box gutter also needs to be correctly sloped to the outlet points in order to prevent ponding (water standing in the gutters and potentially causing corrosion).
Rainheads are an essential design element for buildings where internal box or trough gutters are used. A rainhead or sump is a container located between the gutter and down pipe that aids the flow of water away from the roof. It acts as an external overflow point to reduce water surges into the storm water system and aid the flow of water down the down pipe. Because rainheads are positioned outside, they minimise the risk of water overflow inside a building. The addition of an overflow provision provides even greater protection against water overflow in extreme conditions.
This video from Dam Busters explain how rainheads are installed and works
Common reasons causing plaster walls and ceilings to crack and sag.
Settlement in new homes
Foundation and movement especially for old homes
Very old plaster, deteriorating
Home distorting during strong winds
Loads on ceiling and walls
Settlement in new homes
Wall and ceiling plaster cracking can appear after a few months of a new home being built due to settlement of foundations, timber walls, masonry walls and ceiling joists sagging/moving. This is expected with new homes and can generally be patched by re taping joints but if there are more serious cracks an engineer may needed to assess the issue then area removed and replaced with new plaster.
Foundation movement in old homes
Masonry walls often show stepped cracking commonly due to foundations moving whether soil drying due to droughts, tree roots, unstable soil and poor construction. There are a couple of methods I use when repairing cracks if they are minor but for serious plaster wall cracks usually underpinning may be required or large trees removed.
Old plaster deteriorating
Very old homes, 100 years plus with original lath and plaster simply deteriorate. Sometimes lath and plaster can be patched/restored but if in bad condition it is best to remove entire area and replace using plasterboard or if original plastering is desired I specialise in lath and plaster.
Plaster walls and ceilings in high winds
High winds cause houses to twist and ceiling to move up and down like a large sail. After a period of time this can cause ceiling to have “nails popping” or even collapse. This is very common in garage ceilings as droughts occur and not enough battens or large spacing of joists leaving the plaster ceiling with not enough fixing points to secure the ceiling. There are a couple of plaster repairs that can be carried out to garage ceilings. Please refer to garage ceiling plaster repairs blog post for further information.
Water damage due to blocked or inadequate down pipes, broken tiles, poorly maintained roof, plumbing, and accidents are the common causes. Repairs are generally carried out by removing damaged areas and replaced with new plasterboard.
It is more important to address the issue first.
Check with a plumber whether more down pipes are needed and for added measure install boxgutter / rainwater head as this will prevent flooding into your ceiling.
Roof maintenance is important. Clean cutters, check and unblock down pipes periodically, inspect the roof tiles for any missing or cracked tiles and loose ridge caps.
Insurance claims can be made for plaster repair costs due to storm water damage. Check with your insurer and policy.
Unfortunately common especially to garage plasterboard ceilings. Sometimes an oversight and budget issues or non compliant trades not recognising standards and requirements for certain construction situations. When sighted and addressed early, plaster repairs can be carried out with minimal costs.
Loads on plaster ceiling and walls
Ground floor plaster ceilings can develop cracks due to the first floor movement. Additional weight upstairs, house members, furniture, movement or sagging timber joist are all factors. For walls, additional loads causing wall to distort and plaster wall will crack. A structural engineer would need to assess the cause before and wall or ceiling plaster repairs are carried out.
Differences in temperature especially to larger areas can cause plaster ceilings and walls to crack. Many materials are used in a house and every material expand and contract with hot and cold conditions. There are a few ways to rectify this issue and these can be discussed on site.
Rendering or Solid Plastering is the application of a sand / cement and sometimes lime mix to the construction of buildings to internal and external masonry walls with a smooth or textured final result .
Rendering is mainly aesthetic but can be used for waterproofing and fire rating to walls.
Rendering finishes come in many types to required look such as;
Lath and plaster is a building process used to finish mainly interior dividing walls and ceilings. It consists of narrow strips of wood (lathes) which are nailed horizontally across the wall studs or ceiling joists and then coated in plaster. The technique derives from an earlier, more primitive, process called wattle and daub.
(Lath seen from the back with brown coat oozing through)
In Canada and the United States the laths were generally sawn, but in the United Kingdom and its colonies riven or split hardwood laths, of random lengths and sizes, were often used. Splitting the timber along its grain greatly improved strength and durability. Lath and plaster largely fell out of favour in the U.K. after the introduction of plasterboard in the 1930s. In Canada and the United States it remained in use until drywall began to replace the process in the 1950s.
Each wall frame is covered in lath, tacked at the studs. The lath is typically about one inch (2.5 cm) wide by four feet (1.22 meters) long by 1⁄4 inch (6.4 mm) thick. Each horizontal course of lath is spaced about 3⁄8 inch (9.5 mm) away from its neighbouring courses.
Temporary lath guides are then placed vertically to the wall, usually at the studs. Plaster is then applied, typically using a wooden board as the application tool. The applier drags the board upward over the wall, forcing the plaster into the gaps between the lath and leaving a layer on the front the depth of the temporary guides, typically about 1⁄4 inch (6.4 mm). A helper feeds new plaster onto the board, as the plaster is applied in quantity. When the wall is fully covered, the vertical lath “guides” are removed, and their “slots” are filled in, leaving a fairly uniform undercoat.
In three coat plastering it is standard to apply a second layer in the same fashion, leaving about a half inch of rough, sandy plaster (called a brown coat or browning(UK). A smooth, white finish coat goes on last. After the plaster is completely dry, the walls are ready to be painted. In this article’s photo (“lath seen from the back…”) the curls of plaster are called keys and are necessary to keep the plaster on the lath. Traditional lime based mortar/plaster often incorporates horsehair which reinforces the plasterwork, thereby helping to prevent the keys from breaking away.
Eventually the wood laths became less common, and were replaced with rock lath (also known as “button board”), which is a type of gypsum wall board with holes spaced regularly across it, usually in sheets sized 2 feet (24 in) by 4 feet (48 in) (60 cm by 120 cm). The purpose of the four-foot length is so that the sheet of lath reaches exactly across three wall studs, which are spaced 16 inches (410 mm) apart on centre (United States building code standard measurements). The holes serve the same purpose as the spaces between the wood lath strips, allowing plaster to ooze through the board when the plaster is applied, making the keys to hold the plaster to the wall board.
In addition to rock lath, there were various types of metal lath which is categorized according to weight, type of ribbing, and whether the lath is galvanized or not. Metal lathing was spaced across a 13.5 inch center, attached by tie wires using lathers’ nippers. Sometimes, the mesh was dimpled to be self-furring.
Lath and plaster has been mostly replaced with solid drywall or plasterboard (also a type of gypsum wall board, although a bit thicker), since it is faster and less expensive to install.
An advantage of using lath is for ornamental or unusual shapes. For instance, building a rounded wall would be difficult if drywall were used exclusively, as drywall is not flexible enough to allow tight radii. Wire mesh often used for exterior Stucco is also found in combination or replacement of lath and plaster which serves similar purpose.
Traditional lath and plaster has superior sound-proofing qualities when used with lime plaster (which is denser than modern gypsum board).
In many historic buildings lath and plaster ceilings have a major role for the prevention of fire spread. “They are critical to the protection of horizontal elements such as timber joisted floors, including the flooring on top, which in terms of fire performance is often in a poor condition due to the presence of gaps.
Garage ceilings have been an issue for many years.
Noticeable signs are sagging ceiling, garage roller door jamming or a complete collapse. Common problems are storm water damage and poor workmanship.
Options to repair plaster garage ceilings are;
Re-fixed using screws if not yet collapsed or sagging excessively – less expensive but not fully guaranteed.
Better option is to fix wooden strapping along plaster joints using screws to garage ceiling joists in a cross pattern.
This option guarantees that garage ceiling is secure from collapsing.
With a total garage plaster ceiling collapse or extensive damage, the only option is to replace the collapsed section or entire plaster ceiling. When replacing the entire plaster ceiling I highly recommend fixing metal furring channels / metal battens at 450mm. centres (see pictures below) to truss joists that are often 600mm centres then fixing new plasterboard ceiling using screws and glue. This guarantees 100% workmanship. Of course this is the most expensive exercise.
For more technical information on plaster and plasterboard standards