What You Should Know About Mold During Construction
Mold in building construction or demolition are two things that go together but are usually not given a lot of attention. Building construction or demolition often presents the ideal environment for mold to grow. This can happen when building materials with organic content, environmental factors, and poor building construction procedures converge.
If mold is found on the materials at a site and those materials are subsequently used in the construction, the mold problem can continue in the new building. This exposes the building’s occupants to health issues and the builder to legal liabilities. When erecting or demolishing a building, taking steps to prevent mold can save the builder and owner a lot of trouble.
Mold and mold growth during construction
Mold is a type of fungus that thrives in damp and humid environments with organic materials that the organism can feed on. Mold can grow in finished buildings and on stacked construction materials if the conditions for its growth are present.
Organic construction materials such as wood products and sheetrock easily support the growth of mold. Paper and dust will also promote mold growth. When mold-infested building materials are used in a building, the mold problem will often continue in the completed structure.
If mold grows on a building’s structures or items inside it, the people who live or work in that building will be exposed to several health risks. Health issues that could result from mold exposure include nausea, tiredness, and worsening of symptoms in people with respiratory challenges.
What causes mold to grow during building construction?
The main cause is water incursion that is not handled properly. This may be due to:
- Problems with site drainage, such as when water is allowed to buildup in certain areas
- Stored building materials that are not adequately protected from rain or snow
- Exposing the building to the weather, which leads to installed materials becoming wet
- Suppliers’ failure to ensure that materials are well-dried before delivering them to the site
- Contractor’s failure to treat mold-infested materials before using them in the building
- Poor building design
How to prevent or handle mold growth during construction
The following practical steps will help prevent mold during and after building construction.
- Building materials that are vulnerable to mold should be stored in a dry location which must be raised off the ground. Upon delivery, such materials have to be inspected for mold before being taken into storage.
- Deal with drainage issues around the site. Make sure storm water does not collect around the foundation. Roof drains must be properly mounted and the right size. Pipes that are prone to develop condensation should be insulated.
- Dry-in the building before interior construction begins. Drying-in a building will seal it and keep water from penetrating its interior. This means creating the building envelope before hanging the drywall and installing ceilings or wood flooring.
- Use only materials that have been thoroughly dried in the interior after it has been dried-in. Materials that are even slightly wet will release moisture into the interior and defeat the purpose of drying-in.
- Take immediate steps to dry materials that come in contact with moisture. The longer materials are allowed to stay wet, the deeper moisture penetrates them and the greater the likelihood that those materials will cause mold to grow.
- Periodically inspect the site and building’s interior for new sources of moisture and take steps to remove or control them. Certain building procedures – such as those which use water to control dust – may reintroduce moisture into the building.
- Use building materials that are resistant to moisture, and, by extension, mold growth. One such material is “greenboard,” a type of waxed drywall with better moisture-resistance capabilities than traditional drywall. This is just one example out of several.
- If mold is detected, do not try to remove it until the moisture source is detected and removed. The mold will continue to grow as long as it has access to the moisture that is driving its growth.
- Make sure agreements with suppliers include measures for ensuring that all building materials delivered to the site have been fully dried. Include steps for what to do with materials that have visible signs of mold.
Preventing mold by choosing the right contractor
Mold prevention in building construction often comes down to the builder handling the project. The following questions can help ensure only builders who are competent in this regard are selected:
- Do you have moisture control strategies and response plans for building sites?
- Do you make moisture incursion one of the items on your inspection checklist during the walk-through?
- What mold-resistant materials do you incorporate into your buildings?
- Are your suppliers – particularly lumber suppliers – legally bound to only supply mold-free construction materials?
- Do you have ready access to a professional drying contactor?
- If mold is found in a building shortly after it is completed, how will you handle it?