Quality assurance of energy-efficient and moisture-safe constructions

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The field of energy saving• The developer defines the energy efficiency and quality

demands. • The designers fulfil these demands to a high standard and

high-quality. • Supervision of the work creates the proper conditions for

making a high-quality building.• Workers

• carry out the construction and details as planned• take care that the building materials are kept in dry conditions away

from rain • use proper materials and equipment• use proper tools and working methods• keep the site in good condition, take care of the

weather shielding and the proper temperature

and moisture.• report mistakes to the supervisor and

do not cover up any mistakes.

Utility

The installation of the plastic insulation

Utility

The sealing of the penetrations

Quality assurance of the energy efficient

construction

The installation of the soft heat insulations

The installation of the wind break and the external facing

The installation of the damp proofing

Prerequisites for the quality of an energy efficient and moisture-safe construction

Exercise

Give examples of how the different sections

affect the energy efficiency and quality of

a construction.

Plans and instructions

Materials and elements

Contractors and workers

Equipment and tools

Site

Previous work phases

Conditions

Energy efficient

construction

Discuss

How an energy-efficient and moisture-safe

construction is ensured on site?

• Plans and manufactures’ instructions are read carefully• Durable materials and equipment are used• The work order is planned forehand• Damp proofing, heat insulation and sheathing boards are installed airtight

and sloppy work should not be covered over• Heat insulations and the other places are kept dry• Drying out building moisture is ensured • Everyone does their best with tightness and quality

So the work is made with professional pride!

Checklist:Installation of the sheathing board and cladding

• The seams of the sheathing board are matched to the place on the frame.

• The boards are fastened tight in butt against the skeleton construction.

• Long-term resistance is ensured, if needed, with strips outside of the seams.

• The sheathing board should always be well insulated so the timber frame is in warmer and drier conditions. Only breathable papers should not be used.

• An open ventilation gap is left behind the cladding from down to up.• Ventilation gaps are left under and above the windows.• The gutters, drainpipes, window panels, rocker panels, storm panels

and other cover fillers and drip mouldings direct the rain water away from the wall structure.

• The corners of the sheetmetal work and the details of the joints are made long-lasting.

ChecklistInstallation of soft heat insulations

• The insulation fills the whole insulation space.

• The insulation is installed using light pressure against both the structures and the other insulations.

• Especially insulations under the floor and ducts should be flattened against the surfaces.

The overlapping of the joints, the taping and pressure of the joints, the unbroken and continuous vapour barrier

ChecklistInstallation of vapour barriers

• The vapour barrier foils are overlapped at least 150 mm.

• The airtightness of the overlap is ensured with vapour barrier tape or by screwing the compression panel above the overlap against the frame.

• The vapour barrier foil should not be fixed by rivets alone. Adhesion is ensured with battens, studwork or by taping the rivets

• Clearance is left where the foils join to the structure(EW-EW, EW-R, EW-BF, IF-EW)

• Small holes are taped over with vapour barrier tape before the board work begins.

ChecklistInstallation of plastic heat insulation• The matching joints between the

insulation panels are foamed and installed into butt joint.

• The width of the joints against the structure is 10-25 mm.

• The base of the joint is dry and clean• The sawn edges of the insulation are

cleaned, for example, with compressed air.

• Deep joints are foamed in two phases• The foam gun and flexible foam are used

in jointing.• The last drops from the foam gun are not

used. Change the bottle after the hiss.

Foaming margin

ChecklistLoose-fill insulation• The margin for settlement of the insulation in the roof needs

to be noted, especially under the diagonals and ducts.

• Mineral wool insulation panels between joists reduces settlement.

• The ventilation gap between the facade and the roof should not be blocked with mineral wool. The wind conditions must be checked before blowing loose-fill insulation.

• The base of the loose-fill insulation should not be too flexible. With plastic foam, the maximum gap between battens is 300 mm. 3 mm thick hardboard can also be used between the plastic and the battening.

• In an external wall, the underside of through-holes, furniture supports and electric installations must be filled completely.

Checklistwindow installation

• In concrete framed houses the cement paste is rubbed down on the opposite surface of the frame and the surface is vacuumed up.

• The air tightness of the joint should increase towards the inner surface.

• The tightness of the vapour barrier is ensured by turning the vapour barrier between the window frame and the urethane foaming.

• A foam gun and flexible foam are used when jointing.

• Sealing can also be made by taping the vapour barrier to the window frame with vapour barrier tape.

• The ventilation gap under and above the window is taken into account when fitting trims.

ChecklistHVAC installations• Avoid unnecessary corners and through-holes of the conduits. • Try to site the ducts, pipes and electric installations on the inner

side of the vapour barrier.• The ventilation ducts and pipes must be thermally insulated to

prevent the water condensing in the cold ducts and to heat loss in warm ducts.

• The sensors and thermostats are positioned so that there will not receive a direct blast of ventilation, hot air or cold air.

• Do not tighten the ventilators too much to avoid losing pressure of the ventilation.

• At start up, the direction of rotation of the pumps and the fans must always be checked. Check the water is circulating correctly in the radiators and other heat exchangers. Also check the rotation of the

air current in the exhaust air heat pumps.• The simultaneous use heating and the cooling must be prevented.• Rules for energy-efficient use and maintenance are outlined in the

operating and maintenance manuals.• The indoor air temperature, quality and energy consumption must

be monitored.

ChecklistThe installation of through-holes• Manufactured through-hole collars are

recommended.• The collars are attached to the vapour barrier

foil with vapour barrier tape.• When installing, a margin for movements

must be left. This is because of heat and moisture movements and bowing due to variation in loads.

• In plastic heat insulations, through-holes are sealed with PU-foam.

• Ducts and pipes must be made totally tight because of the risk of condensation. Long-term resistance to the tightness must be ensured in the through-holes.

Question: What are the most important effects on quality when increasing the insulation thickness?

• To reduce heat loss and avoid outer parts of the structure getting cold. To avoid a decrease in fault tolerance.

• Structures that are more sensitive to moisture should be shielded by board.

• The vapour barriers of the envelope and shield boards must be installed tightly to prevent microbes growing in the structures and ensuring healthy indoor air.

Thermal imaging – tightness of the envelope

• In the cold season it is easy to check the tightness of the envelope with thermal imaging. In summer it is possible to use smoke to locate leaks.

• Thermal imaging can decrease leaks and other quality problems.

Thermographic imaging – tightness of the envelope

Critical points of tightness:

• joints of the top floor• junction of the floor and the base • junction of the roof and the external

wall• junction of the intermediate floor and

the external wall• junction of the bathroom and the sauna• window opening and the doorway• HVAC through-holes • ventilation panels• joins of the vapour barriers

ChecklistThe building’s moisture and condition on site

Remember:

• Structures must be tight from inside and ventilated outside from the sheathing board.

• If the jointing of the facia is made only after the first heating phase, the ventilation of the outer side must be stressed.

• Ventilation gaps of the elements must be checked and the quality of the gaps must be demanded from the suppliers.

• Heating and a relative humidity of approx. 50% speed up the drying.

• The moisture level and sufficient drying of the concrete structures must always be measured before they are covered by airtight covering or cabinets.

• The quality of the work shows for decades – do not rush.

Methods of quality assurance

• Moisture measurements• Thermographic imaging• Tightness test• Checklist• Log book• Field book• Samples of waterproofing

Professional pride

Expert knowledge needed to build an energy-efficient home:• People skills with clients, designer and builders• Problem-solving skills; everything

can not be anticipated beforehand• Ability to work meticulously with a high level of

professional pride

Discuss in pairs: What is professional pride?

Discuss in pairs : What increases professional pride and what reduces it?

Discuss in pairs : How could the positive factors be increased and how could the negative factors be removed?

Closing discussion

What did you learn?

Attitude counts!

Give examples of energy waste in buildings and how to avoid it.

The good practices and principles required for the energy efficient building have been included in the teaching material. The writers are not responsible for their suitability to individual building projects as such. The individual building projects have to be made according to the building design of the targets in question.