Thinking your house is in the risk of rising damp? You’re not alone. Reports say
What is Rising Damp?
Rising damp is a particularly rare type of damp. It caused by moisture moving up through walls and affects internals and externals of housing walls. You will find porous plasterwork or timber around the affected area.
Rising damp caused specifically by groundwater being sucked up through bricks microtubes, kind of. This kind of water normally
TIP If you found an affected area that does not grow after time, it could be caused for high humidity and long raining period.
A quick fix is to use specialist paints and primers. That should be enough to fight mould and minor damp.
Rising damp solutions –
What is the best rising damp treatment?
Rising damp – Solution 1: Install Ventilation
This solution works for homes with an underfloor cavity. Maintaining or improving ventilation with circulating air-flow by an air pump. This way, damp air keeps being replaced by dry air all the time.
Depending on how large your flooring is, you can estimate how many air vents to be installed. And try to improve airflow as much as you can.
TIP: In most case, big air vents every meter away should suffice to keep the subfloor dry.
In the case of permanent damp or severe impact, mechanical ventilation is highly recommended. This work would cost much more money, up to thousands, but in the
Warning: Having concrete slab replaced does not help in the long-term. It’s better to improve
Rising damp – Solution 2: Using a Damp-proof course (DPC)
A damp-proof course is in a form that plays a role as a barrier to rising damp.
- A polyethylene sheet normally will be placed at 20cm above ground surface and as close to inside-house floor level.
- In some cases, the type of chemical DPC is rather a better choice.
- DPC is installed by keeping replacing section by section throughout the wall base or replacing mortar joint with DPC inch by inch.
- For better results, moving drainage far way from the wall as much as possible, or at least 50mm from the wall.
Rising damp – Solution 3: Chemical damp proof course
As stated above, a chemical kind of DPC has many advantages over the physical damp proof course.
- Drilling holes along mortar joints to insert chemical DPC
- Chemical DPC is applied by pressure injector
- It usually cures after 2 – 6 weeks.
If you’re not sure what you’re doing, it’s best to let professionals do the job.
Rising Damp Signs – What to look for?
1. Moldy-brick walls
Moisture moves up when you have a solid-flooring. You should have the damp proof course as soon as possible.
2. Roof gutter leaking
Try to seal it as soon as possible, fix the leak from pipes.
3. Tiles grout color changed
Perform regrouting is needed as tile gaps are just perfect for dampness penetrating.
4. Peeling plaster
5. Mildew in places
Mould grows in warm and damp conditions. It happens mostly in bathroom ceilings. Try to kill mould by spray or wiping off damp ceiling once in a while.
Check the source of this dampness and treat it with new DPC as soon as you can.
7. Paint efflorescence
Treatment required as soon as possible. It includes leaking fix and damp proof course. Efflorescence can quickly spread out and erode even the strongest materials.
How do you fix rising damp as professionals?
The most popular way to treat rising damp is creating a new DPC on the affected structure (walls, roofing).
Here are two ways Tech-Dry company use to treat rising damp for your home.
Fix rising-damp with TechDry DPC Cream
DPC Cream by TechDry is the type of water-based silicone. This helps to form a permanent damp-course with its super 80% silicone concentration.
What makes this TechDry DPC Cream work?
- DPC can be injected by professionals or yourself
- Siloxane in the DPC cream will be absorbed into bricks and mortar-beds
- Silane or siloxane after being absorbed will form a long lasting polysiloxane damp course.
How to inject DPC Cream the right way?
- Find the mortar line. It will be used as a new Damp Proof Course.
- Mark evenly so that you will drill 3 holes along the length of each brick.
- Drill holes with 1.2cm diameter and set the depth at 1cm less than the wall thickness.
- Use a vacuum cleaner to clean all the dust after drilling.
- Use DPC Cream with a caulking gun to inject into mortar bed as instructions.
How to calculate DPC Cream you need?
- As the company says one cartridge can be applied for 1.5m for single-brick or 0.75m for double-brick.
- A 5-litre tub can be used for 30m single-brick and 15m double-brick work.
- A 20-litre tub can be used for 120m single-brick and 60m double-brick work.
DPC Cream by TechDry Advantages
- Can be treated from
- Use caulking gun from any local hardware store
- Friendly with
- High Silicone Concentration 80%
Stop rising damp with TechDry Damp-Course Fluid
TechDry DPC Fluid will react with the minerals already in the walls by dampness to form a permanent damp-course
Steps to treat rising damp with TechDry DPC Fluid
- Remove all skirting boards or plasters to open up the bottom layer of bricks.
- Drill 10mm-holes on a 45-degree angle on every single brick at first mortar line.
- Use TechDry applicator kit with the cartridge to fill in DPC fluid as instruction
Calculate TechDry DPC Fluid needed
TechDry DPC Fluid only come with 2 quantities
- 5-Litre type could be applied for 3m single-brick work (half for double-brick)
- 20-Litre type could be applied for 13m single-brick work (half for double-brick)
What size Applicator Pack do I need?
TechDry Applicator has 2 sizes available:
- Pack of 30: Able to treat 3m single-brick work
- Pack of 120: Able to treat 13m single-brick work
Note: TechDry Applicator Packs are manufactured to be re-usable.
Frequent Asked Questions
What causes rising damp on internal walls?
Rising damp caused specifically by groundwater being sucked up through bricks microtubes, kind of. This kind of water normally consists of salts that make building materials eroding.
What are the signs of rising damp?
- Moldy-brick walls
- Roof gutter leaking
- Tiles grout color changed
- Peeling plaster
- Mildew in places
- Paint efflorescence
What is a salt attack?
It happens the same way rising damp caused. Underfloor water with soluble salts is being sucked up to the wall and it is being absorbed into stones, bricks.
How do damp-courses fail?
When DPCs are installed poorly, they are not forming a complete barrier along the affected walls. Also, new pavements or gardens setup could be the reason.
Reasons a Damp Proof Course failed:
- Poor installation
- Garden or paving recently installed causes bridging
- Bridging caused by renovations.
- Chemical attack
- Penetrating during DPC installation
Does rising damp cause health problems?
Rising damp can cause several health problems. They range from
I hope you find this guide helpful and gave you the confidence to do the DIY project. Or at least, it helps you understand how professionals will do in this situation.
Check out more in our Renovation Section for more guides and tips!