As building get older, the after-care and maintenance become more important. We wish to share what are the common defects found at residential building, so you can take good care of your building and make your living much more enjoyable.
When there are defects, the performance of your building will be affected. We wish to share with you, what are the methods you can use to repair those defects.
With proper maintenance and right repair, your building will not deteriorate so soon and you can even live comfortably as the building age but enjoying the nice atmosphere.
Building components will degrade over time and their performance will be weaken as they age. When there is defect, there will be loss of performance. You can see the changes in their appearance and/or composition.
In order to rectify the defects, you need to know the causes of defects at the building components. Most of the times, a defect in one component may lead to damage in another link components. Therefore, it is important to discover the defect early.
Regular inspection and routine preventive maintenance will help to identify defects early in their building life. Symptom like damp spots, hairline cracks will give you pre-warning of the early sign of defect in the building components/materials.
Most Observable Defects
There are two kinds of defects you are most likely to come across: dampness and cracks.
Dampness refers to the presence of excessive water in the building component. It will likely cause defect to the component like wood rot and metal rusting. When there is dampness at the wall, there will be mould growth in the wall. Before repair, you need to identify the source of dampness and eliminate it. Otherwise, the problem may occur again after the repair.
Common area to look out for dampness are:
- the damp proof course and its damp proof membrane
- concealed pipes
- flashings
- roof drainage area like the gutters and downpipes
- rain penetration at external wall
Crack will occur when the force on the building component is greater than what it can withstand. The usual repair of cracks can be done by filling the cracks with cement or polymer based filler. If it is tile’s crack, you will need to replace the affected tiles.
Types of defect on each component and its repair
There are various components in a building and each one of them will have different kinds of defects. You will need to adopt different repair method to rectify those defects.
1. Reinforced Concrete Defects and how to repair
RC may deteriorate due to aggressive substances go into it from the external environment. Sometimes, it may due to internal impurities in the concrete causing carbonation and pH reduction. When there is large presence of moisture within the RC, the re-bar inside may corrode or concrete expansion or crack or spalling due to loss of strength.
Way to repair the crack at RC
- Fill up the crack : drilling hole at close intervals along the crack and inject with epoxy.
- Seal the crack: enlarging the crack and fill it with suitable joint sealant
- Repairing spalling concrete: (1)removing concrete at spalled area and use wire brush to remove rust found on re-bar and apply 2 coats of anti-rust paint (2) applying bonding agent to the surfaces and patch repair with cement based or polymer materials (3)painting repaired area
2. Brickwork Defects and how to repair
Defects could be due to brick itself or the sealing mortar and mostly due to dampness. This is especially obvious for those brick walls which exposed to rain.
Common defects found on the bricks are
- (a)Efflorescence – the salt deposit can be removed by repeated washing with hose and brushed off between washes. Use cement-lime-sand mix (1:1:6) for persistent efflorescence.
- (b)Mould growth – remove with fungical wash. Brush away dead mould with a wire brush.
3. Roof Defects and how to repair
Roof defect will result in leaking from the building ceiling. You may re-roofing, repair or replacing those defects.
You can consider applying special coating to improve waterproofing.
4. Plasterwork Defects and how to repair
Common defects for plaster are cracks and detachment. These are due to improper preparation or shrinkage of the substrate and insufficient key for the plaster.
Ways to repair:
(a)to repair the crack, “V” notch the crack and clean with brush and vacuum clean. Damp the crack before filling it with plaster or filler material. Remove excess plaster with a damp sponge.
(b)for delaminated plaster, remove all the loose material with a wire brush and create a “V’ notch at the edges of the old plaster. If there is residue on the wall, clean away. Re-plaster it.
5. Ceramic Tiles, Stonework Defects and how to repair
Tiles and stonework defects are mainly cracks and detachment. You need to treat the defects first, before you do the replacement.
6. Paintwork Defects and how to repair
Most of the defects for paintwork are dampness and crack in the substrate (like plaster).
Way to repair: you need to treat the dampness and its substrate problem. First, you must remove the old paintwork and treat the substrate problem. If the substrate is the plaster and it cracks, you need to repair the plaster before you do your new paint.
7. Footpaths common defects
- stagnant water
- overflow/flooding/ponding
- skidding
- delamination of finishings
- potholes
8. Water pipe leaking
Very common you will encounter water leaking issues among all kind of buildings, be it residential, industrial or commercial buildings. The knowledge and experiences in dealing with the problem will be useful when it happens.
The copper pipe could be corroded after years of wear and tear like below:
