Many defects of this construction period are the same as homes of the construction periods before. However, with this construction period, we have 2 new entrants in particular that deserve attention: concrete rot and asbestos. Especially during this construction period, it is important to be extra sharp. It is advisable in almost all cases to have an architectural inspection when purchasing a home from this period. If you are buying an apartment in a block of flats, then it is important to look very closely at the VvE documents. Is there already an asbestos inventory report, what is the condition of the roof, the condition of the sewerage, what do we know about concrete rot, etc.
Below you will read about the main construction defects are from this construction period.
Poorly ventilated cavity wall
It may be that ventilation openings in the exterior wall have been sealed or closed off (e.g., by planters) so that the cavity wall is not or not sufficiently ventilated. It may also be the walls are insulated. This can cause moisture penetration, condensation from the inside or, for example, rising damp. If there is a wooden first floor then beams can rot or mold or fungus can develop in the crawlspace and wooden structural floor.
Light interior walls
Light interior walls (mostly plaster) may lack sound insulation. This can make it very noisy in the house.
Concrete Rot
Concrete rot is 1 of the biggest dangers of this construction period. Concrete rot occurs when the reinforcing steel in the concrete starts to rust. This is bad for the adhesion of the concrete to the reinforcement and thus detrimental to the strength of the concrete element and thus a problem for the entire structure. Concrete rolling can occur when oxygen can get to the reinforcement or due to penetration of chlorides (salts).
The 2 most notorious structural floors with this problem are the:
-Kwaaitaal floors occurring in the construction period 1965-1983
-Manta floors occurring in the construction period 1965 – 1981
With these types of floor, for example, concrete rot can quickly develop in the concrete floor elements when the crawl space is damp. If you don’t realize this in time, you may literally end up sinking through the floor one day. Very important to look carefully if not this type of floor in the home. For the building inspector or real estate agent, this means: flashlight on and into the crawl space to check it out.
Outdoor Sewer
The exterior sewage system may consist of vitrified clay pipes. These will one day give way and this can cause leaks in, for example, an existing basement. Also, you can then get subsidence in the ground.
Lead pipes
There may be lead water pipes and/or lead drain pipes in the home.
Lead water pipes can cause lead poisoning. Lead drain pipes have the same bad humor as vitrified clay sewer pipes: they are guaranteed to fail you once and cause leaks. If you are remodeling and there are lead pipes somewhere, make sure you always replace them.
Oil tank
In these types of homes, there may still be an oil tank in the yard. It is then important to know whether it has been remediated and whether there is a Kiwa certificate for this.
Steel lintels
Steel lintels can oxidize (if not maintained in a timely manner). When this happens, they expand and cracks can appear in the exterior walls.
Concrete lintels
Cold bridge problems can occur in concrete lintels. Simple explanation: the wall is nicely insulated with cavity wall insulation but the concrete lintel above the window frame is not. This forms a ‘cold bridge’. A cold bridge attracts condensation. This can cause mold to form at the lintel. Also, the lintel may become subject to concrete rot. The steel reinforcement in the lintel has then started to rust, and will expand causing the lintel to crack and lose its load-bearing capacity.
Wooden foundation piles
Wooden foundation piles were used in the Netherlands until about 1970.
During this construction period, foundation piles made of softwood were widely used. These posts are extra sensitive to bacterial infections and fungi. The biggest problem with wooden foundation piles, however, is when they become dry due to varying groundwater levels. What can then occur is pile rot with all its consequences.
Wooden Floors
If there is a wooden floor, then wooden floor joists have been used whose beam heads are anchored in the wall. Moisture rising in the walls can cause the post heads to rot and the beams to have to be replaced. However, fungus, mold, and woodworm are also common problems with wood floors. During purchase viewings we try to pay attention to whether the floor is bowing (which can indicate rotten beams), we try to measure moisture in the wall (moisture can indicate rotten beam heads) and we see if there is a crawl hatch available for us and/or a structural engineer to look into to see if everything is okay.
Plastic window frames
The older type of plastic window frames can begin to discolor. What you also see a lot is that leaky windows (the glass has become that blurry) or broken/worn rubber glazing profiles. A final problem is that sometimes these types of frames are not properly placed in the facade.
Stony floors
These can lead to moisture problems by these they can start to condense.
Bobbins
These should not be longer than 1 meter in 1 piece. Sometimes this is not the case, which can cause the lead to crack and cause leaks.
Sandwich panels
These insulation panels for the sloping day may be formaldehyde containing. This can be dangerous to your health.
Elektra
During this construction period, we no longer expect hazardous canvas wiring, but current wiring may be so outdated that it may also become hazardous. A short circuit can occur and cause a fire. Therefore, it is important to have the status of this wiring looked at by a specialist.
Asbestos
Yep, there it is! Asbestos. I would almost be surprised there is not or once was asbestos somewhere in these types of homes. Where you may often encounter asbestos includes:
– On barn roofs
– As a chimney flue
– Sewerage
– Plate above or behind the central heating boiler
– Behind the heater
– Flooring tarpaulins
– Vinyl tiles
– Window Sill
– Wall plate behind washbasin
– Crawl space hatch
– Roof boarding
– Meter box
– On doors
– In system walls
– Privacy screen on the balcony
– In the ventilation duct
– In drain pipes
– In kit of frames
– Underfloor slabs
– Cover plates
Tip: Do you think you might have asbestos in your home and want to remove it because you are remodeling, for example? Always get a specialist involved. If you start sawing and drilling into asbestos material and fibers are released that you breathe in, you can become seriously ill from this years later.