Top
Cart 0
Cart 0

HEMPCRETE - HEMPRO - PCS - LINTELS 

FREQUENTLY ASKED QUESTIONS

HEMPBUILD LTD. SUPPLY SUSTAINABLE CONSTRUCTION MATERIALS WORLDWIDE

NATURAL HEMPCRETE BLOCKS - HEMPFLAX INSULATION - NATURAL LIME PLASTERS

062 Hempbuild Sustainable Products Isohemp Hempcrete.jpg

 HEMPCRETE BLOCKS FAQ’s

A list of commonly asked FAQ’s relating to Hempbuild’s Isohemp Hempcrete Products and associated materials. Hempbuild Isohemp hempcrete blocks are great for glued, non-load-bearing masonry for building healthy, natural insulation and partition walls. It is a versatile product recommended by professionals for both new builds and renovations, from complex restorations to extensions, family homes, community buildings and commercial buildings.

If you have a question that you cannot find the answer to, please contact us - we are more than happy to assist.


 
 

+ What are the Hempbuild Isohemp hempcrete blocks composed of?

The Hempbuild Isohemp hempcrete block consists of hemp, hydrated lime and hydraulic lime. They are 100% natural and locally sourced raw materials.

+ Are there health benefits to Hempbuild Isohemp hempcrete blocks?

They are non-toxic and resistant to mold, pests, and fire, making it a good choice for both new build construction and an excellent choice for a healthy home.

+ Can Hempbuild Isohemp hempcrete blocks be used for new build?

Yes, Hempbuild Isohemp hempcrete blocks are associated with a load-bearing structure to create envelopes for new constructions. Several possibilities are possible: wooden construction, load-bearing blocks or the IsoHemp Hempro system.

+ Can Hempbuild Isohemp hempcrete blocks be used for interior renovation?

Yes, Hempbuild Isohemp hempcrete blocks allow the interior to be renovated by keeping the inertia of the building and allowing the old walls to breathe. They are particularly suitable for the interior insulation of old brick or stone walls.

+ Can Hempbuild Isohemp hempcrete blocks be used for exterior renovation?

Building a second, exterior wall of your home is the optimal solution to achieve high thermal insulation for the entire building, while still having all the finishing options for your facade. Whatever your exterior insulation project might be, Hempbuild Isohemp hempcrete blocks are a perfect choice.

+ What are the possible finishes of Hempbuild Isohemp hempcrete blocks indoors?

The interior finishes are varied: indoor ceiling, clay, tiles, wood cladding, etc. PCS plaster, a natural render based on natural plaster, lime and sand ideal for finishing your walls and ceilings with a very smooth finish.

+ What are the possible exterior finishes of Hempbuild Isohemp hempcrete blocks?

The exterior finishes are varied: siding, plaster, bricks or briquettes, etc.

+ What are the dimensions of the Hempbuild Isohemp hempcrete blocks?

The hemp block has a length of 60 cm and a height of 30 cm. Only its thickness varies: 6 cm, 9 cm, 12 cm, 15 cm, 20 cm and 30 cm.

+ How many thicknesses are there?

There are 6 thicknesses: 6 cm, 9 cm, 12 cm, 15 cm, 20 cm and 30 cm.

+ What is the maximum weight of a Hempbuild Isohemp hempcrete block?

The maximum weight of a Hempbuild Isohemp hempcrete block varies according to the thickness and humidity content :

  • Block of 60 mm: 4.6 kg

  • Block of 90 mm: 7.1kg

  • Block of 120 mm: 9.2kg

  • Block of 150 mm: 11.5kg

  • Block of 200 mm: 15.3kg

  • Block of 300 mm: 23kg

+ Are Hempbuild Isohemp hempcrete blocks load-bearing?

No, Hempbuild Isohemp hempcrete blocks are not load-bearing. They must be used in tandem with a supporting structure. Several construction systems can be used: the Hempro system, wooden frame, post-beam system, or supporting masonry.

  • However, it is self-supporting up to 10 metres high depending on its thickness.

+ How do the Hempbuild Isohemp hempcrete blocks adhere?

The Hempbuild Isohemp hempcrete blocks are laid in a thin joint with a natural adhesive mortar. This is a lime-based mortar that is used instead of traditional mortar. The installation is done in a thin joint of around 3 mm using a glue comb or a notched trowel.

+ What thickness of joint must be created to glue the Hempbuild Isohemp hempcrete blocks?

The Hempbuild Isohemp hempcrete blocks are laid in thin joints around 3 mm thick.

+ Which tools are used to cut the Hempbuild Isohemp hempcrete blocks?

Several cutting tools can be used :

  • A Widia manual saw blade;

  • An electric Alligator saw;

  • A band saw (recommended for larger sites).

+ Can Hempbuild Isohemp hempcrete blocks be placed on the ground?

Yes. Whether it’s a renovation or a new construction, the use of Hempbuild Isohemp hempcrete blocks on the ground makes it possible to insulate the slabs and is suitable for supporting a screed. This technical solution is fast and simple. The placed product is dry, which makes it possible to apply the finish very quickly.

Two systems exist for insulating your ground with hemp blocks:

  • Slab – block – screed

  • Draining mass (telford base) – stabilised – block – screed

+ What are the advantages of Hempbuild Isohemp hempcrete blocks for ground insulation?

  • Excellent compressive strength (15 T/m2).

  • Speed of execution and performance over time.

  • High technical flexibility such as the application of floor heating, the application of ducts in the screed, etc.

  • Easy and fast cutting.

  • Laying of insulation in just a few hours for a complete house.

+ Can Hempbuild Isohemp hempcrete blocks be placed on the roof?

Hemp blocks can only be placed on flat roofs. For the insulation of flat concrete roofs, it’s very easy to install hemp blocks. Whatever the configuration, they are fast and easy to apply. Slope concrete is applied on which the waterproofing of the roof is then laid.

+ What are the advantages of Hempbuild Isohemp hempcrete blocks for roof insulation?

This solution has the advantage of quick and easy implementation on site. With its high thermal inertia, the Hempbuild Isohemp hempcrete blocks prevents overheating of the building in summer and guarantees excellent resistance over time.

+ Can the Hempbuild Isohemp hempcrete blocks be grooved and sheathed inside?

Yes. To make grooves for electricity or other technical networks, it’s recommended to use a grooving machine and a suitable hole saw.

+ What is the thermal conductivity of a Hempbuild Isohemp hempcrete block?

The lambda (= thermal conductivity) of an IsoHemp block is 0.071 W/mK.

+ What is the specific heat of a Hempbuild Isohemp hempcrete block?

The specific heat of the Hempbuild Isohemp hempcrete blocks is 1600 J/KgK.

+ What is the density of a Hempbuild Isohemp hempcrete blocks?

The density (= dry apparent mass density) is 340 kg/m³.

+ What is the lifespan of a Hempbuild Isohemp hempcrete blocks?

As long as the building exists and the Hempbuild Isohemp hempcrete blocks is protected by a finish (plaster, brick, etc.), it will not degrade and its technical performance will remain intact.

+ Can Hempbuild Isohemp hempcrete blocks be left visible?

For situations where thermal and acoustic insulation is required, it’s essential to render the Hempbuild Isohemp hempcrete blocks. They are not airtight and it’s the block + rendering system that creates the technical performance. For applications where maximum sound absorption is desired, it’s possible to paint the wall directly using a spray gun or to attach a fixator to the wall.

Can Hempbuild Isohemp hempcrete blocks be left outside to store them?

Hempbuild Isohemp hempcrete block pallets can be stored outside for 3 months and stored for 2 years if the pallets are covered and protected from rain.

+ Why choose Hempbuild Isohemp hempcrete blocks for your new construction?

Hempbuild Isohemp hempcrete blocks are suitable for all types of projects. In addition, they guarantee the success of your project and have many advantages such as:

  • Thermal and acoustic performance essential to comfort.

  • Natural regulation of humidity.

  • Flexible design.

  • Long-term durability.

  • Ease of implementation.

  • A wide choice of finishes: brick, parging, cladding, etc.

+ What are the fields of application of Hempbuild Isohemp hempcrete blocks?

Hempbuild Isohemp hempcrete blocks are particularly suitable for the construction of residential houses, doubling of existing walls on the inside or outside, as well as industrial subdivision and apartments.

+ After how long can a ceiling be placed on Hempbuild Isohemp hempcrete blocks?

One week after laying the Hempbuild Isohemp hempcrete blocks if the wall is dry.

+ Can the Hempbuild Isohemp hempcrete blocks be glued directly to the walls?

This gluing technique is used only for the implementation of Hempbuild Isohemp hempcrete blocks with 6 cm thickness. The gluing of the blocks is done only against an existing uniform and flat wall. It is recommended to use a special bonding mortar that is suitable for the gluing substrate according to the manufacturer’s instructions. Do not use bonding against a wooden element.

+ Is it possible to tile directly on the Hempbuild Isohemp hempcrete blocks?

Yes it is possible.

+ Must a foundation be made before laying the Hempbuild Isohemp hempcrete blocks? If so, how thick?

Hempbuild Isohemp hempcrete blocks cannot be placed on the ground directly. It is necessary to provide a foundation with a rotproof insulating block between 15 and 30 cm thick according to the stability calculations before laying the hemp blocks.

+ From where is it necessary to fill the space between the existing wall and the Hempbuild Isohemp hempcrete blocks?

From 3 cm, it’s recommended to fill the gap with a mixture of ProKalk lime and hemp and a little water.

+ How many Hempbuild Isohemp hempcrete block courses can be made in the same day? Must it be allowed to dry after 3 or 4 courses or can the blocks continue to be laid?

After three courses, it’s recommended to wait between 1 and 2 hours before resuming the masonry work.

+ After how long is a wall dry?

The wall is dry after one week if it’s placed in good conditions. The state of the wall depends on the state of the blocks during the implementation. If the blocks have been wetted by rain before implementation, the drying of the wall will take longer.

+ Must a dual flow ventilation be used despite the Hempbuild Isohemp hempcrete blocks?

Dual flow ventilation is not required when using Hempbuild Isohemp hempcrete blocks. Ventilation is nevertheless essential to ensure correct air renewal, because if the blocks are open to water vapour and rendered, they become airtight.

+ Are the Hempbuild Isohemp hempcrete blocks anti-allergic?

Hempbuild Isohemp hempcrete blocks are not implicated in any risk of allergies. In case of risk, be sure to use a primer and a completely natural paint as a finish.

+ How many 60 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

120 Hempbuild Isohemp hempcrete blocks.

+ How many 90 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

78 Hempbuild Isohemp hempcrete blocks.

+ How many 120 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

60 Hempbuild Isohemp hempcrete blocks.

+ How many 150 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

48 hempcrete blocks.

+ How many 200 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

36 Hempbuild Isohemp hempcrete blocks.

+ How many 300 mm Hempbuild Isohemp hempcrete blocks are there on a pallet?

24 Hempbuild Isohemp hempcrete blocks.

Hempbuild Hempcrete Vertical Line Website.png

ISOHEMP HEMPRO SYSTEM

The IsoHemp Hempro system is a method of loadbearing for hempcrete block walls. The system consists of Hempbuild Isohemp hempcrete blocks that have been specially adapted to allow the casting of a reinforced concrete frame inside the hempcrete wall which will then support the construction and roof.


 
 

+ What are the benefits of the Isohemp Hempro system?

  • Speed of implementation.

  • Homogeneity of the wall: only one product.

  • A healthy and natural product.

+ What is the performance of the Hempro system?

The Hempro system can be used for low-energy, very low-energy and passive buildings.

Hempbuild Hempcrete Vertical Line Website.png

PCS INTERIOR PLASTER

PCS interior plaster is an economical, durable and superior solution. The interior plaster is a well-judged mix of natural plaster, limestone and sand. Ideal to coat your walls and ceilings both for renovations and new builds. It combines the easy application of natural plaster with the benefits of limestone, such as the natural moisture regulation of the living space in your home or building.


 
 

+ What is the composition of PCS natural interior plaster?

Hempbuild's Isohemp PCS interior plaster is composed of a balanced mixture of natural plaster, lime and sand.

+ What are the application media of Hempbuild's Isohemp PCS Interior Plaster?

Hempbuild's Isohemp PCS interior plaster is a single-layer primer that is applied to all rough and absorbent substrates, both in new construction and in existing building renovations. It can be applied to hemp blocks, concrete blocks and trellises, cellular concrete and terracotta blocks and bricks. It is suitable for all interior walls and ceilings.

+ Can it be used on outside external surfaces too?

No, Hempbuild's Isohemp PCS interior plaster is a primer exclusively reserved for indoor applications.

+ What thickness of Hempbuild's Isohemp PCS interior plaster must be applied to hemp blocks?

Between 10 and 20 mm.

+ What are the benefits of Hempbuild's Isohemp PCS interior plaster?

  • A primer open to the diffusion of water vapour.

  • A healthy, natural and sustainable product.

  • An economical solution.

  • A smooth and ready-to-paint finish.

  • Ease of implementation.

+ How long must you wait between laying Hempbuild's IsoHemp hempcrete blocks and starting the installation of Hempbuild's Isohemp PCS interior plaster?

One week after laying the hempcrete blocks if the wall is dry.

+ Is Hempbuild's Isohemp PCS interior plaster safe and healthy?

Yes, Hempbuild's Isohemp PCS interior plaster is a 100% natural product that is not harmful to health.

+ What finish can be achieved with Hempbuild's Isohemp PCS interior plaster?

Hempbuild's Isohemp PCS interior plaster provides a white finish that is smooth, modern ready to paint.

Hempbuild Hempcrete Vertical Line Website.png

ADHESIVE MORTAR

A natural adhesive for Hempbuild’s Isohemp hempcrete blocks. An adhesive mortar that has been specially developed for the implementation of construction using hempcrete blocks for interior and exterior use. It is a lime based mortar that is used in place of traditional mortar, applied as a thin seal of approximately 3mm by using a dedicated adhesive comb or trowel.


 
 

+ What is adhesive mortar composed of?

It’s a mortar based on lime.

+ Is adhesive mortar natural?

Yes, adhesive mortar is a 100% natural product.

+ What is the thickness of the joints to use to glue the hempcrete blocks?

The hempcrete block installation is done in a thin joint of around 3 mm using a glue comb or a dedicated trowel.

+ What is the average consumption for 3 mm thin joints?

The average consumption is 2 bags per pallet of hempcrete blocks.

+ Does adhesive mortar dry quickly?

The drying time of adhesive mortar is 36 to 72 hours.

+ What is the usage time of adhesive mortar?

The usage time is one hour.

+ What is the average consumption of adhesive mortar?

The average consumption is 2 bags per pallet of hempcrete blocks.

How many bags of adhesive mortar are there on a pallet?

There are 40 bags per pallet.

Hempbuild Hempcrete Vertical Line Website.png

Miscellaneous FAQ’S

Miscellaneous questions relating to various hempcrete construction questions and also certifications.


 
 

+ Where do the raw materials used for the production of Hempbuild's Isohemp hempcrete blocks come from?

Isohemp maximise the short route and have different suppliers in Belgium, France and the Netherlands.

What can be used for window or door openings?

It is recommended to use IsoHemp lintels. IsoHemp lintels are prefabricated hemp concrete lintels with a reinforced concrete core used for opening doors and windows in hemp block masonry. They are perfectly suited to new constructions and interior or exterior renovations.

+ Are Hempbuild's Isohemp hempcrete blocks fire-resistant?

With an excellent fire reaction (class B for the rendered block), they offer up to 2+ hours of fire resistance depending on the finish and the thickness of the block used.

Where do the raw materials used for the production of Hempbuild's Isohemp hempcrete blocks come from?

Isohemp maximise the short route and have different suppliers in Belgium, France and the Netherlands.

What can be used for window or door openings?

It is recommended to use IsoHemp lintels. IsoHemp lintels are prefabricated hemp concrete lintels with a reinforced concrete core used for opening doors and windows in hemp block masonry. They are perfectly suited to new constructions and interior or exterior renovations.

Are Hempbuild's Isohemp hempcrete blocks fire-resistant?

With an excellent fire reaction (class B for the rendered block), they offer up to 2+ hours of fire resistance depending on the finish and the thickness of the block used.

Can we buy Hempbuild's Isohemp hempcrete blocks direct from IsoHemp?

No, Isohemp are manufacturer's and do not sell direct. Hempbuild Sustainable Products Ltd are a major distributor who have our products in stock.

+ Do you have a technical approval?

Yes, we have a technical approval issued by CSTC for IsoHemp hemp blocks. You can downloaded it in our technical documents section.

+ Can you show a positive carbon balance for the production of Hempbuild's Isohemp hempcrete blocks?

Yes, the manufacturer Isohemp have indeed conducted a Life Cycle Analysis on the products and on their manufacturing process.

This analysis identified the stages of the Life Cycle where the main impacts of Hempbuild’s Isohemp hempcrete blocks occur and validated the positive carbon balance of the hempcrete blocks.

The impact in the Global Warming category has a value close to -100kg of CO2 stored per 1m3 of hemp blocks. This negative value indicates long-term CO2 storage that is beneficial to the environment. This LCA can be consulted and downloaded in our technical documents section.

Hempbuild Hempcrete Vertical Line Website.png