Senior Greenhouses – strong, spacious, customisable
Senior Greenhouses are made with the same strong ‘box section’ aluminium profiles as Helios Greenhouses providing optimum strength and value for money. Senior Greenhouses are lower at the sides and ridge than other Helios models. This range is essentially a package deal version of our Helios Greenhouses giving you best bang for your buck.
- Very Strong Helios box section profiles
- Integral aluminium base profile (under the four walls)
- 4mm clear toughened glass
- Full length rubber glazing strip to secure the glass
- Sliding doors, roof and louvre vents as detailed under the price
- Full length rainwater downpipes
- Stainless steel nuts and bolts
- Decorative finials and ridge crestings (powder coated models only)
- Powder coated frame (if selected) in a standard
- Instruction manual and assembly DVD
- Delivery in kit form by truck
Strong ‘box section’ Aluminium profiles
Corner Glazing Bar
Rubber Glazing Strip
Roof Window with handlese
Stainless steel nuts and bolts
Decorative finials and ridge crestings
Price your very own Janssens Senior Greenhouse
Type of Finish
Polyester powder coating protects the aluminium frame from tarnishing with exposure to the elements and is available in a wide range of attractive colours. It is a durable long lasting finish, a bit like enamelling.
Aluminium which has not been protected against weathering is called ‘mill finish’, this suits people who just want a working Greenhouse without regard to how it looks.
The Senior Model has a choice of two colours, Green (RAL 6009) and Black (RAL 9005).
Janssens’ louvre vents are a generous size (opening of 69cm x 93cm) giving great ventilation. The louvre vent frame is always supplied in black, but being a neutral colour it nearly always blends in. Automatic openers are available for louvres but we suggest you automate roof vents but leave louvre vents manual (unless extreme weather is forecast they can be left open in summer and closed in winter). We have only allowed for basic ventilation in the basic Greenhouse price and you can never have too much ventilation on a warm summer day, so we recommend adding at least one .
For exposed locations decorative ‘spandrels’ will reinforce the structure greatly, increasing the ability of the Greenhouse to resist buckling in the wind. These attractive spandrels will be in the same colour as your frame and are fitted to every second glazing bar.
A single Sliding Door is included as standard in each Senior Greenhouse. You can upgrade this to a double sliding door to provide a wider door entrance if desired.
Single Sliding Door
Double Sliding Door
Sliding door entrance with lowered threshold
The standard door entrance has a threshold bar going across at ground level which is 118mm high (to step over). For most customers this is not an issue but where a lower threshold is desired – for example for wheelchair access we offer a service to modify the door entrance to be only 40mm. Customer can place after installation of the Greenhouse concrete slabs or raise the floor level inside and outside to be flush with this so there is effectively no lip.
Automatic Vent Openers
Simple devices which open and close roof vents automatically for you according to temperature. They contain an industrial wax-like substance inside a cylinder which expands and contracts with according to the temperature and pushes or pulls a rod that opens or closes the automatically. The temperature at which they open and close can be adjusted by hand but you cannot manually open the vent. The cylinder containing the wax-like substance is a consumable item but typically lasts a number of years and can be easily replaced. Generally in windy weather automatic openers are cooled down by the wind and so close the vents.
Thermoforce HD3400 Automatic Vent Openers
This robust opener has a strong closing force. It has a maximum opening of 35cm (14″) and comes powder coated in a black finish. Its opening range is between 15C and 25C.
Bayliss Hydraulic Check Autovents (for more exposed locations)
The Hydraulic Check Autovent has a small hydraulic damper which only allows the vent to be opened slowly but it can shut quickly, thus protecting the roof vent. The hydraulic check Autovent is advisable in areas where severe conditions are encountered. It can be set to start opening at temperatures between 16C and 23C. Supplied with a satin anodised finish.
Don’t be fooled by the name, a seedbed can fulfil many purposes. First and foremost it provides a comfortable surface on which to pot up and tend to plants. You can use it to display plants on and it gains you additional space in the Greenhouse. A seedbed can be fitted with capillary matting to assist even water distribution among your pot plants or you can fit an electric thermostatically controlled heated mat in it to make a propagator.
Multiple units can be fitted. They can be fitted along the full length of the side and/or across the full width of the gable ends. Each seedbed frame is made from aluminium in the same colour as your Greenhouse and the tongued and grooved plastic panels which make up the bottom are white.
The Janssens shelf is an aluminium section 115mm wide. It is useful for small pot plants and odds and ends like gloves, secateurs and other small odds and ends. A shelf also adds to the already powerful strength of the Greenhouse. It is supplied in the same colour as your Greenhouse.
Janssens’ attractive shade screen comes in 3m lengths and is fitted like a curtain, it will slide allowing you to pull it over exactly the area you want to give shade to and push it away when you want more light. Equally useful for shade loving plants that do not want direct sunlight or customers who want to enjoy sitting and reading a paper in the shade!
Greenhouses may look quick and to build but there is a considerable amount of time and a lot of parts involved, however if you enjoy DIY this is often very enjoyable. With our professional and courteous construction service you will know that the job has been done right first time.
We quote for construction on an individual basis, to obtain a quotation for this Greenhouse that you are pricing please click on the button below.
If you are buying a ‘glass to ground’ greenhouse (i.e. not a dwarf wall model) and have a long established flat and level lawn, a concrete foundation is not needed and we can build directly onto it – but otherwise our construction service price is based on any foundations, ground works and walls being prepared by the customer in advance of our arrival on site.
Details on foundations are available on the instructions tab on this website page, and we will be pleased to discuss any queries you have and if necessary provide further drawings specific to your Greenhouse once an order has been placed.
Our construction service is subject to some terms and conditions (link to the details here):
If ordering our construction service we bring the Greenhouse kit with us so this section is not relevant. If you are buying your Greenhouse to self‐build delivery is by truck (lorry) normally. If you have restricted or unsafe access for a truck you will need to order the van delivery service.
Delivery by Truck
When a Greenhouse is bought in kit form (for DIY assembly) at the price shown, it is shipped from the factory and delivery is made with a large lorry fitted with a tail lift. The driver will use a hand operated ‘pallet truck’ to take a tall pallet of glass off the lorry and he will carry the boxes containing the frames off and put them down beside or near to the lorry. The driver’s pallet truck can go onto concrete, tarmac or paving – but it won’t move on gravel or grass (or up steep slopes). The delivery service is basically to the roadside or wherever the driver can access with his pallet truck. It is essential that there be safe parking for the lorry at your entrance if he is unable to park off the road at your property. If this is not possible please choose delivery by van or our construction service (or nominate a location for delivery where a truck can access from where you can arrange for others to move it to your site).
Delivery by van
If delivery in a lorry is not possible we offer a service where we take delivery of your Greenhouse, and deliver it to you on a scheduled delivery run to your area. There is a charge to cover the extra handling and transport costs to provide this service and the lead time will be extended (we can confirm at time of order). We will offload your goods with care to beside our van, the panes of glass can either be stood up against a wall in your garage (they cannot be left lying flat) or we can bring a pallet and stack the panes into it. If ordering this service please advise which you prefer.
The lead time is the estimated length of time from when your order is placed to when delivery is made. This is a guideline only as lead times may vary according to demand and logistical considerations.
DIY Kit Lead Times
Normal lead time is five weeks.
If a low door threshold or our construction service is ordered add two weeks.
It would be nice if you could make a visual representation of this – like the chart shown below but with the correct information shown in it as described above.
Assembly video for Helios Greenhouses
Tips and tricks
Model illustrated is the 3.1m x 4.58m
Eaves height (H1)
Ridge Height (H2)
Max. Doorway Width