Trunk CLT provided a full design, engineering, and supply and erection service for this detached house in Hertfordshire. Trunk CLT is headed by Mike Jacob and Jim Johnstone. Mike is a Chartered Construction Manager, and Certified Passivhaus Tradesperson, director at Trunk low energy and has worked in the emerging low energy construction sector for many years. Jim is a CLT and solid timber construction industry specialist. Jim has extensive experience delivering groundbreaking bespoke one off and multi-storey timber projects in London, Nationwide and abroad. It’s a positive blend of technical, practical and project management skills which ensures real quality of construction  together with passivhaus standards.

With extensive forward planning at each junction Truck CLT have been able minimise the heat losses from both a an air tightness and thermal bridging point of view. The building has a complete CLT structure with 180mm to 160mm of Schneider Holz wood fibre insulation, The building fabric is secured with a range of airtight tapes and high performance membranes all supplied by Partel.  This level of detail is consuming but where these points can slow down the project they are critical towards achieving long term efficiency and a safe building fabric. Also Truck CLT always makes up for this in other areas like for instance the projects principle structure was erected in just two days, admirable to say the least!

Project build-up

• Highly insulated floor slab
• Fully constructed CLT core framework
• Internal Air tightness and vapour check layer DB90 from AMPACK
• Externally insulated by Schneider best wood fibre natural breathable insulation
• UV stable Monolithic TPU technology – Amapatop F Black from AMPACK
• Counter batten and beautifully finished with a cedar cladding

​It’s one of the nicer, and technically solid projects we’ve been involved in recently. It’s also fantastic to see how the finishes can be exactly as desired.

Erection of first floor CLT with combination of Ampacoll XT60 providing a permanent air tight seal and continuing that redline of Schneider Wood fibre insulation.

Both internal and external eye pleasing finishes.

WUFI Analysis of woodfibre insulation

WUFI analysis Woodfibre insulation

Dooroge woods is a development of 37 luxury 3, 4 and 5 bedroom detached homes close to swords in Dublin. The aim of the developers was to deliver a high performance development that would deliver in terms of quality in all aspects, not just a A2 rated property.
Impressive airtightness was demanded and so Ramstown Timber frame were appointed together with the Ampack Airtightness range. Nicky Stafford of Ramstown timber frame is experienced in passive house building and airtightness and was an interesting choice have worked in ‘one off’ housing most recently.

The quality control procedure from passive house single dwellings is welcomed in multi-unit development and has seen the development meet or exceed the brief where airtightness is considered. 

Greyfield developments as modern developers are acutely aware of the air quality issues and are keen to continue to develop a long term reputation for high standards.

Accordingly we were brought in to present LUNOS decentralised ventilation systems. The issue of quality control with ducting installation and future cleaning was  a factor when LUNOS were appointed. 

The chosen LUNOS demand controlled ventilation system (DCMEV) operate on a completely decentralised system – Ducting is right through the wall via pressure controlled inlets and intelligent extracts that adjust automatically relative to time temperature and humidity. LUNOS fans have expected lifespans of over 30 years and can cost €5.00 per year to run for the overall system. With this system indoor air quality is assured for decades.

LUNOS Silvento smart extract fan

LUNOS Silvento complete

LUNOS ALDR fresh air inlet

Ampack Ampatex DB90

The building appears uncomplicated but achieving such clean lines, finishes and the hidden low energy precision requires a builder with an impressive skillset. Greentec Eco homes were selected and again delivered to the usual high standards.

A comment from Lenni Antonelli at passivehouseplus.ie sums up Lester Naughton and Niall Dolan of Greentec.

       I ask Naughton if hitting the passive house airtightness target of 0.6 air changes per hour was straightforward. “With this guy,” he says, pointing to builder Niall Dolan, “yeah, it was.” Dolan in turn praises the quality and detail of Naughton’s design drawings. 

We’d like to think the tapes and membranes from Ampack helped then along the way ! In this project Niall and Lester used Ampacks DB90 & DB2 membranes internally and externally Protecta and Aero. This essentially applies the market leading 10 year system warranty of Ampack to the high performance timberframe.

It’s a question we get asked quiet often – is there a rule that I can apply in general terms too all flat roofs? Unfortunately there isn’t due to the mix of factors that affect moisture. This is an area we specialise in and can provide a market leading system warrantied flat roof constructions. Read more about our unique warranty here

• Orientation – North facing roofs have lower solar gain and therefore receive less heat and will have lower levels of back drying.

• Colour of outer membrane – Light coloured membranes reflect more sunlight and therefore have lower levels of heat transfer to the roof than the same roof with a dark membrane.

• Insulation location – Is it above the Deck , within the deck, under it or a mix of both !

We have below provided 4 solutions that can cater for all types of flat roofs providing an option for safe solutions. Insulation is neutral (Can be by any manufacturer)

CONSTRUCTION 1

Un-ventilated construction -Insulation on top of the supporting structure.

Quality of application and blower door testing is critical towards achieving results.

Construction structure from the inside to the outside

1. Supporting structure
2. Air sealing / vapour barrier – SD >100- AMPACK CENTO
3. Insulation
4. Closed roof system part – Possibly Slip / separating layer
5. Closed roof system part – Sealing the gap ≥ 1.5%
6. Closed roof system part – Extensive protective layer
7. Final outer roof covering

CONSTRUCTION 2

Ventilated construction:

Quality of application and blower door testing is critical towards achieving results. The air layer should be larger than currently accustomed to at 100mm to allow satisfactory airflow.

1. Final ceiling
2. Cross battens
3. a)Air sealing / vapour barrier or - AMPACK DB90 or AMPACK VARIANO b) Airtight supporting structure,
4. supporting structure
5. Insulation
6. Roofing MEMBRANE - AMPACK PROTECTA PLUS OR AMPACK AERO
7. Slope layer (battens)
8. Air layer – **NB recommended 100mm for adequate air flow.  
9. Supporting structure for sealing
10. Closed roof system part – Possibly Slip / separating layer
11. Closed roof system part – Sealing the gap ≥ 1.5%
12. Closed roof system part – Extensive protective layer
13. Final outer roof covering

CONSTRUCTION 3

Un-ventilated construction -Insulation within and on top of the supporting structure.

Quality of application and blower door testing is critical towards achieving results. Vapour control layers for construction 3 should always allow for backdrying  and have an SD of less than 10- ideally variable – see AMPACK VARIANO. The Glaser method will fail to calculate this system accurately and therefore always recommend a  site specific WUFI analysis.

This construction has a minimum rule of thumb between the insulations – 2/3 to 1/3 with a  minimum of 1/3 of insulation above and 2/3 below. The upper part can be above 1/3 which improves the situation. This buildup can mitigate for light membranes and colder roofs due to shading.

1. Final ceiling
2. Cross battens
3. a -Air sealing / vapour barrier or - AMPACK VARIANO b- Airtight supporting structure,
4. supporting structure
5. Insulation
6. Construction waterproofing – Not for building physics AMPACK AERO
7. **Additional Insulation – Minimum 40mm**
8. Closed roof system part – Sealing the gap ≥ 1.5%
9. Closed roof system part – Extensive protective layer
10. Final outer roof covering

We simulated this buildup in WUFI using a  worst case scenario – North facing and a lightly coloured membrane. We allowed for a stressed situation using a q50 of 5 (Air infiltration) at the plywood bord)

We have been asked to simulate this buildup without the inner insulation but still with the variable – Ampack Variano membrane  - We know it not to be a recommended buildup but are able to demonstrate in WUFI that the water content % in the air layer or batten space ranges is not ideal. The medium is the difference here- Air/Insulation and the buffering capacities.

When compared with the same space when full filled the water content is between 0.5% and 2%. (Average 1kgm3)

CONSTRUCTION 4

Unventilated construction -Only in special cases – insulation within the structure

Non vented structures have a lower tolerance for error. Quality of application and blower door testing is critical towards achieving results. Vapour control layers for construction 4 should always allow for backdrying  and have an SD of less than 10- ideally variable – see AMPACK VARIANO. The Glaser method will fail to calculate this system accurately and therefore always recommend a  site specific WUFI analysis.

1. Final ceiling
2. Cross battens
3. a-Air sealing / vapor barrier or - AMPACK CENTO b-Airtight  supporting structure,
4. supporting structure
5. Insulation
6. Closed roof system part – Possibly Slip / separating layer
7. Closed roof system part – Sealing the gap ≥ 1.5%
8. Closed roof system part – Extensive protective layer
9. Gravel Protection layer

References : 

A new timber frame construction was erected adjacent to the older cottage and within 20m of the sea - this challenging location has meant that superior building protection solutions were chosen to ensure long term building security.

The Ampack Airtight system was achieved to enerphit levels of airtightness and to manage vapour in the building. External and internal systems were supplied by Ampack care of Partel which essentially ensures the structure avails of the market leading 10 year warranty by Ampack  

Specialist insulation materials were also used to improve the performance. Cellulose insulation pumped at 65kg/m3 was used in the exterior timber frame walls with 100mm of Woodfibre insulation outside of this. The internal service cavity has 50mm flexible woodfibre insulation (both woodfibre and cellulose are used to keep the house cool in the summer).

Thermal bridging was addressed in all areas using Compacfoam underneath the timberframe and doors and the entire roof has woodfibre insulation over the rafters. Heico fixings were used throughout.

The LUNOS decentralised heat recovery ventilation system was chosen due to guaranteed low sound levels, ease of installation and low running costs. We also used the smart LUNOTHERM element.

Internally the soundproofing of floors used a combination the Idikell system from Ampack and 20mm of rigid high density woodfibre insulation.

The project has finished and the results in terms of location and comfort are exceptional.

(Airtightness, Thermal bridging, Windows and Insulation are all in keeping with many passive house projects recently undertaken but certification was not a requirement from the clients. Building performance and comfort were the primary factors)

Project management, specification and supervision by Corbwell Design. Low energy materials and specification by Partel. Original architectural design by others.

Ampacoll® Sillskin 

Ampack’s newest tape is on that improves quality in timber framed constructions by offering a flexible, long lasting watertight seal for difficult junctions such as window installations or parapets.

Ampack have a long established and tested range of butyl tapes and accessories.
Sillskin is  a self-adhesive, highly elastic butyl rubber sheet that can be used to cover parapets in wooden buildings under construction (until the windows are installed) or for the watertight formation of window sills. Also ideal for bridging large joints and gaps.

Advantages

• >300 % expandability
• Separate liner to facilitate mounting
• on windows
• Easy unrolling thanks to robust cardboard rolls

Technical details

The products can be purchased here 

Located on the outskirts of a Berkshire village, the old water tower – now certified passive house – is that the home of Owner and co-founder of Gresford architects -Tom Gresford.

The property has been certified as a Passivhaus – a title granted to buildings that use natural strategies of heating and cooling, instead of counting on electrical systems.

Gresford Architects aimed to show that passivhais need not be what has become to be known as a typical passivhaus – instead providing a vernacular high quality modern design.

“We have aimed to create a house that is on the cutting edge of sustainable design, yet eschews the hair-shirt approach to sustainable living that many people think of when considering environmentally friendly homes,” Gresford Architects said.

“The house is conceived as a modern interpretation of the timber-framed barns of the area, that when seen from the distance reads as a simple, traditional, agricultural building,” they added. ”On closer inspection it reveals itself as a crisply designed, carefully made, contemporary interpretation of the historic buildings it draws inspiration from.”

The building is 2 storeys high, with a gabled roof and a facade of black-stained timber weatherboard.

Gresford with the able assistance of the services of the in demand Mike Jacob of Trunk Low energy opted to utilise a wide timber framed wall using a selection of Airtight tapes and membranes from Ampack. Ampack now offer BBA certified external and internal systems that complement their 30 years of real time experience in the field of airtightness.

The partnership for this project has recently evolved with the formation a new joint venture taking advantage of the strenghts of Trunk Low Energy and Gresford architects TGPassivhaus. Both parties have a history of delivering ultra low energy efficient homes, often using ecological materials.

Project Specifics

Architects: Gresford Architects Ltd

Certifier: Warm: Low Energy Building Practice

Building Society: Ecology Building Society

Project Management: Trunk Low Energy Building

Main Contractor: MBC Timber Frame

Specialist tapes and Membranes: Partel

We are delighted to announce that our Windtight systems have received British Bord of Agrément certification. The certification also includes approval from the National House Building Council (NHBC). 

Protecta BBA certificate

Aero BBA certificate

DB90 BBA Certificate

Ampack’s BBA certification includes Ampack’s external systems -Ampatop Protecta, Ampatop Protecta plus, Ampatop Aero and Ampatop Aero plus.  The range of associated Ampack tapes is also listed as ancillary parts in the certificate. The certificates are the second and third in a new range of certification for Ampack following the grant of BBA certification for Airtight systems.

The entire Ampack range comes with a unique ten year warranty. Ampack’s guarantee covers not just the replacement cost of materials but also any associated damages and the cost of any repairs, which makes it unique in the market. This warranty is particularly pertinent as Architects and Engineers assume greater levels of responsibility when certifying. The use of the Ampack system can essentially provide security over the building fabric.

Established in 1946, Swiss supplier Ampack is a market leader in building envelope protection products, and was reportedly the first company to commercially produce vapour checks. As a result Ampack have products installed and tested for over 35 years.

Ampack have been at the forefront of building protection systems for decades and have developed a name stands for high quality proven product’s. Ampack offer one of the largest ranges of airtight and windtight systems including a range of Butyl, Nail seal, UV stable tapes and liquid weldable roof membrane Ampatop SEAL – Another innovative product with a liquid weldable surface that can be installed as low as 5′ degrees.

A well-sealed building envelope is the key to energy efficiency. Regrettably, the job of priming surfaces so that they can be properly sealed with insulating materials is often difficult and time consuming. With its new Ampacoll® Airmax spray primer, the Swiss supplier Ampack now promises to make the work a whole lot easier.

Professional and conscientious priming is hard work. Applying a sealant with open cans, trays, rollers and brushes takes a lot of time and working on overhead surfaces with liquid sealants tends to be strenuous. Nonetheless, it’s simply not an option to skip the priming. This is because porous and absorptive building surfaces, low temperatures and moisture can prevent you from achieving a tight seal. This is where the new spray primer Ampacoll® Airmax by Ampack plays such a helpful role because it allows you to complete the priming work quickly, easily and safely.

Ampacoll® Airmax serves as an adhesive base for Ampacoll adhesive strips on porous or rough surfaces such as masonry, plaster, concrete, rough-cut wood, and wood-fibre panels. Simply spray the solvent-containing, synthetic rubber Airmax in the corresponding width to the clean, dry and grease-free surfaces you need to seal in order to form a basis, and then apply the adhesive strips or panels. The spray primer makes it easier to complete overhead and vertical work. The new spray primer is also especially effective when you’re forced to work in difficult conditions involving moisture and low temperatures ranging down to -5°C.

Make sure to cover any sensitive surface elements before applying the spray. Thanks to the double-rotating spray nozzle, you can also precisely aim and adjust the spray to one of three different levels of volume. After application, the saturated surface begins to harden, with the ventilation time ranging from 10 to 40 minutes depending on the temperature and the surface properties. Once it dries, Ampacoll® Airmax remains sticky and provides a perfect substrate for all Ampacoll adhesive panels and strips.

Spray primer for Ampacoll adhesive strips on porous surfaces, such as masonry, plaster, concrete, bare wood, soft wood fibre board, etc. Suitable for use in difficult conditions (cold, damp).

• Sprayable, faster than with a brush
• Short drying time
• Permanently tacky
• Makes overhead and vertical work easier

What is it and why is it changing how we upgrade older homes?

We are used to seeing SD values in airtight membranes – LDA is different in that it lists an a value – 0.004m3/(h*m2).  The a value describes the quantity of air passing through the layer. (The SD vale relates to the humidity or vapour). While the a value is not currently a defined standard the reference value in the industry for an airtight layer is <0.01m3/m2/h.

This solution starts with higher humiditys and the quality of application is (As it is with all VCL’s) important. To assist with this AMPACK have include integrated tapes on both sides of the membrane and has the same incredible strength we have become accustomed to from AMPACKs exterior membranes.

When we consider quality of application is is important to understand why – a 1mm wide gap can allow 360g water per day – such errors can create issues in any VCL system and as always we recommend a blower door test. In this case it should be carried out when LDA has been installed and before the windtight membrane (PROTECTA is installed).

Data_sheet_Ampatex_LDA-0.02-plus_lr_en