Under Construction:Preservation Concerns During Construction and Renovation

LYRASIS Preservation ServicesFunded in part by a grant from the National Endowment for the Humanities, Division of

Preservation and Access.

Unit 5

Unit 5

– Potentially Harmful Construction Materials

– Reducing the Harm– Post Construction– Cleaning the Buildings

Potentially HarmfulConstruction Materials

• Many gases, dusts, and fibers have the potential to speed up the deterioration of collections. The can be harmful to people as well.

• It is important to be aware of what types of construction materials are dangerous and what can be done to reduce the exposure to humans and collections.

Potentially HarmfulConstruction Materials

• Volatile organic compounds (VOCs) are those materials that are readily volatized (given off as a gas) and can affect indoor air quality. Other dangerous gases are emitted through the use of construction equipment. Welding, for example, can produce ozone, carbon dioxide, and nitrogen dioxides. Ozone or nitrogen dioxide can irritate the respiratory tract and mucous membranes.

Potentially HarmfulConstruction Materials

• Dust and fibers are released during cutting or sanding. While many dusts are not harmful to humans, others may include lead based paints or asbestos dust, both of which could be quite harmful. Asbestos and lead-based paint must be removed by qualified contractors and disposed of following EPA guidelines. Individual states may have additional guidelines.– http://www2.epa.gov/asbestos– http://www2.epa.gov/lead

Construction Materials:Reducing the Harm

• What can you do to reduce the risk to materials and humans from pollutants?

Construction Materials:Reducing the Harm

• If possible, remove staff and collections from areas where that might be exposed to dangerous materials, especially if either is particularly vulnerable. If you can not remove them, then establish responsibility and procedures for controlling any dust or other pollutants generated by construction. Provide adequate ventilation for activities that generate fumes.

Construction Materials:Reducing the Harm

• It may take up to a year for materials in new construction to finish off-gassing. A good indicator of when it is safe for materials is when the “new” smell has disappeared. In the meantime, air system should be operated at maximum outside air for 60-90 days to facilitate the removal of construction off-gassing; after this purging period, replace all air filters in the HVAC system.

Construction Materials:Reducing the Harm

• Finally, use non-toxic building materials whenever possible; not only are they better for the environment, but they are also better for people and collections.

• For a list of environmentally-friendly materials:– http://www.buildinggreen.com/m

enus/

Post-Construction• After the construction has been completed,

expect and plan for a period of adjustment, especially in areas such as the HVAC and security systems. You will need to work closely with facilities and security staff to help work out kinks in the new set-up.

• Drainage should be carefully watched. Hopefully any plumbing problems will have worked themselves out before the end of construction, but there is always a chance of leaks. Closely monitor the space after heavy rainstorms.

Post-Construction• It may take some time for the HVAC

system to adjust the environment to the desired temperature and humidity. Monitor the HVAC system closely, and avoid moving materials until environmental monitoring indicates a stable environment.

• Clean shelving before placing collections on them. By cleaning and vacuuming materials before the move, you can avoid bringing dirt into your newly renovated space; however, cleaning may be incorporated into the shelving process.

Cleaning Buildings• Keeping spaces clean during

construction requires constant vigilance, but it is especially important if your collections and people remain in or near the space during construction. After a project in finally complete, the building and helving should be thoroughly cleaned again to remove any dirt, grime, or other materials that may harm people or collections.

Cleaning Buildings• There are many different cleaning methods

that one can use, and all have advantages and disadvantages, but none should be used directly on the materials themselves.

• Water

• Chemical

• Mechanical

Cleaning Buildings• Water is one of the safer

means of cleaning buildings and storage areas. It softens dirt and rinses deposits from surfaces without the danger of chemicals. Be wary of steam cleaning however, because the high temperatures and increase in humidity can be harmful to collections.

Cleaning Buildings• Another option is to use

chemicals that will react with the dirt to hasten its removal; deposits are rinsed away with the water. Chemicals may more easily remove dirt than water alone, but be aware of environmental and health concerns to humans and collections on the inside of the building and to animals and plants outside of the building.

Cleaning Buildings• A final method of cleaning

after construction is mechanical in nature and usually involves grit blasting, grinders, or sanding disks that remove dirt by abrasion. Usually the surface is then rinsed with water. The resulting dust from this method, when done on the outside of a building, can enter or coat surrounding buildings. If done on the inside, the dust can spread into other rooms or the HVAC system, potentially harming collections and people.

Cleaning Buildings• Whichever method, or

combination of methods you use, you should educate yourself on the potential harmful effects and try to minimize them by following directions closely and using methods with the least potential for harm.

• Consult with facilities staff or risk managers to determine which methods are most appropriate for your building.

Cleaning Historic Buildings• Special care must be taken when cleaning a

historic building. Inappropriate cleaning or waterproofing of masonry buildings is a major cause of deterioration at historic sites.

• First, make sure that “dirt” is actually harmful to the building. What you may think is dirt may in fact be weathered portions of the building itself. Attempting to clean it would in fact be removing part of the structure.

Cleaning Historic Buildings• Another reason to determine the nature of the

“dirt” is because different types of soil and grime require different cleaning methods. For example, soot and smoke require different cleaning methods than bird droppings. In addition to identifying the substances on the building, it is important to determine what the building itself is made of so that the cleaning products you use do no damage to the structure.

Cleaning Historic Buildings• For example, acidic cleaners can be quite

harmful to limestone or marble. If you cannot identify the substances yourself, or for assistance in identifying appropriate cleaning methods, contact a building conservator, geologist, chemist, or preservation architect. It is better to do nothing than to harm accidentally cause harm to the building.

For more on this topic, see Assessing Cleaning and Water-repellent Treatments for Historic Masonry Buildings, by Robert C Mack and Anne E Grimmer available at http://www.nps.gov/tps/how-to-preserve/briefs/1-cleaning-water-repellent.htm

Unit 5 QuizWhat Have You Learned?

Unit 5• Question 1: What can reduce risk to

materials and humans from harmful pollutants?– A: Use non-toxic materials whenever possible.– B: Keep doors open when working.– C: Remove staff and collections from areas of

harm.– D: A and C– E: A and B– F: B and C

Unit 5• Question 1: What can reduce risk to

materials and humans from harmful pollutants?– Answer: D: A and C

• Using non-toxic materials and removing collections and staff are always good ideas. Keeping doors open may not be adequate for ventilation needs. Ventilation and proper venting should be concerns of the pre-construction process.

Unit 5• Question 2: Water is one of the safer

ways of cleaning.– True or False?

Unit 5• Question 2: Water is one of the safer

ways of cleaning.– Answer: True

• Whatever method you use, be sure to follow proper cleaning methods closely and use the safest technique for the material.

Thank You!Contact us if you have any

questions.

LYRASIS Preservation Servicespreservation@lyrasis.org

1-800-999-8558