The basement is a real treasure: it offers a lot of usable space in many different ways which can be crucial especially for smaller homes. However, many basements are damp and have leaks, making them unusable for creating other rooms. Before starting any renovation project you will need to waterproof it.
Steps
Step 1. Calculate the perimeter of the house
Make sure that the slope of the ground around the foundation allows the water to move away from the building. The land around the foundations will usually be lower than the surrounding land, causing the ground to sink and lean towards the house. If necessary, add soil against the foundation to create a 5 cm drop in the surface every 30 cm from the house. Make sure the ground surface is at least 15cm below the foundation plate so you don't have any contact with the ground which can cause the materials to deteriorate over time.
Step 2. You will have problems with the surrounding terrain
Make sure that the gutters are clean and that they drain the water at least one and a half meters from the foundations.
Step 3. Pay attention to bushes and other plants near the foundation
Rotten roots can create a sort of channel for the water, making it slide down to the foundation. The plants should be kept at a certain distance from the house and on a slightly inclined plane in order to direct the water away.
Step 4. Try waterproofing the walls with a special product if you have small leaks
Some products expand and become part of the wall when they dry. Others are more similar to waterproof concrete which requires the presence of moisture to form its waterproof structure: if it is applied in areas where there are small leaks these will be isolated as the product will "surround" them. The problem with these solutions is that the water in the ground under the cellar floor or at the foot of the walls is subjected to strong pressure.
Step 5. Repair defects in concrete walls such as cracks and the places where pipes and bars pass through it
A crack in the wall could cross it all the way to the outside and become a potential channel into which water would infiltrate. For cracks that are not subject to thermal or structural movements, expanding products are very effective. Another method is to inject epoxy construction resin directly into the crack. It is generally best to rely on an experienced repairman. DIY kits are less reliable.
Step 6. Consider installing a drain pit
It is essentially a hole in the basement floor that contains a pump. When the water level inside reaches a certain level, the pump is activated and removes the water from the well by discharging it outside the house several meters from the foundations. Skill and experience are needed to perform such a job, as you need to use a jackhammer or otherwise to make a hole in the concrete, dig, put a lining, connect the pump itself and bring the pipes to the pump. on the outside.
Step 7. Try building a crawl space if the problems related to water are serious
It is a system of pipes that run below the floor level and along the entire perimeter of the basement. Installing such a system is similar to manhole work, but requires cutting and removing a 30 cm wide strip of floor along the perimeter, digging a 30 cm deep ditch which is then filled with gravel placed around the pipes, and then cover everything again with concrete. The crawl space will still need a well and a pump for removing the water.
Step 8. Use bentonite, a clay mineral known for its ability to absorb large amounts of water
It is usually pumped from the outside: it slips into the empty spaces and passages used by the water to end up inside the foundations and seal them. It is the same material that is used to insulate tunnels, manholes, sewers, shafts, elevator shafts and so on.
Advice
- Before starting any renovations, take a close look at the basement during heavy rain. If you can go a year without leaks then you will have no problems in the future (at least as long as you keep the gutters clean and the foundations tended).
- Beware of salt and calcium deposits that form on the concrete due to water infiltrations (white spots). These MUST be removed before using any type of insulation. This is the most common cause of waterproofing failure. You can do this by abundantly wetting the wall with muriatic acid and then scratching. Then rinse the area abundantly with water and then remove it from the floor. Normally you will need to do several steps and you will see the acid react with the deposits on the wall.
- Building a new house is the perfect time to isolate it. Plastic rolls and polystyrene sheets work, but when filling the foundation they can break causing infiltration. This system is also no longer in line with the directives of many nations. Remember that the waterproofing works if it is intact on the surface, protect it with a cloth until use.
-
Regardless of the type of insulation you use, always follow the instructions to obtain a satisfactory result. If you rely on low-skilled workers, the work could be inaccurate.
When cutting concrete, make sure you have plastic rolls hanging from the ceiling to the floor to close the affected area
- Battery operated pumps are available. They are excellent for those wells that have a continuous flow of water inside them because in the event of a power failure or failure of the main pump they can continue to work.
- When installing the sump pump be sure to follow local plumbing guidelines. Many systems require a one-way valve to prevent water from going from outside to the pump.
Warnings
- Mold can be a serious health problem. Using a dehumidifier to keep the basement dry is a good idea.
- If the waterproof paint does not work, you will have to relieve the external hydrostatic pressure by letting the water in. Then you can use a base above the floor without breaking the bottom of the basement.
- When cutting concrete always use protective goggles and a mask or respirator.
