DIY Conservatory Construction Guide

conservatory roof replacement Building a self build conservatory is actually quite a straight-forward task and if you are a competent DIY enthusiast you will find adding a new conservatory to your home is relatively easy and not as daunting as it may first appear.

The following is designed to provide a general guide to the process of installing a new DIY conservatory and whilst not intended to be a detailed construction guide should provide you with the basics.


You have two choices with regard to the type of conservatory base. You can either select a traditional excavated base or you can use a pre-fabricated steel base which will speed up the installation process.

Traditional Base

If you choose the traditional base route you may prefer to employ a local builder to build the base for you as the accuracy of the brickwork is vital in ensuring that your new conservatory can be installed easily and efficiently. Your DIY conservatory supplier will provide you with the base plans to suit your selected conservatory and the base must be constructed exactly to these plans. Using an experienced builder to build the base should ensure that the base is built square, to the correct dimensions and that the footings are excavated correctly. If drains need to be re-routed your builder will have the necessary experience to do this for you during the course of construction. Always agree the cost before work commences and ensure you check the base yourself when the builder has finished to make sure you are happy with the finished result. It can be difficult to get a builder back on site once he has moved onto his next job and any discrepancies in the brickwork could cause problems during the conservatory installation.

Of course you can construct the traditional base yourself and many of our customers have done so but it is time-consuming and very hard work so the savings you will make here by doing-it-yourself will need to be justified against the amount of free time you have to do the job and your expertise in building the foundations and laying bricks.

Steel Base

Installing a pre-fabricated steel base is much quicker and easier than constructing a traditional base as there are no large excavations to undertake so there is minimum disruption to your garden and no need to move any drains. These bases are normally made to order, delivered in kit form and are quite straight-forward to install by two persons over a couple of days or so. If your conservatory features dwarf walls, these will normally be provided as steel cassettes with a variety of external finishes including brick tiles or alternatively, supplied ready for rendering. The base itself is fixed to the wall of the house and sits on adjustable legs that are seated onto concrete pads making it very easy to level the floor which will normally be supplied with insulation and often comes complete with flooring. A steel base can be a cost effective alternative base for your new self build conservatory, especially when you compare construction times and the fact that there is little disruption to your garden. Once completed, these factory built conservatory bases are often very difficult to tell apart from a traditional constructed base. You could even take the conservatory with you when you move house!


Most DIY conservatories are supplied complete with installation instructions that are designed for the novice installer and will cover fixing the walls of the conservatory, installing the conservatory roof and glazing the conservatory structure.

In general terms these instructions will walk you through fixing the French door, the welded cill, the conservatory windows, the corner posts and the conservatory roof. The most important factor to continually check when installing any conservatory is to ensure the frames and cill remain plumb and level throughout the construction. All screw fixings and their positions should be in accordance with the guidelines provided by the DIY conservatory supplier.

The roof structure will include an eaves beam that will sit on top of the window and door frames, a ridge beam or wall plate that will be fixed to your house wall and glazing bars that will connect between the ridge or wall plate and eaves beam. All components should be supplied factory cut, marked and pre-drilled ready for fitting and apart from trimming the guttering to size there should be no need for you to cut any of the roof components. The roof layout plan will enable you to identify which component and which glazing panel should be fitted in which position. Where the conservatory joins the house you will need to fit lead flashing to form a weatherproof seal.


With the conservatory walls and roof installed your next task will be to glaze the roof. If you have chosen polycarbonate roof glazing this is a relatively simple task and involves placing the glazing into position and knocking on the PVCu cappings to form a weather tight seal. The roof plan will indicate the required position of each panel. If you have chosen a glass roof the process will take longer due to the additional weight and nature of the material.

Budget DIY conservatories may be supplied with the windows and door factory glazed but made to order conservatories are generally supplied with windows and doors unglazed. Not only does this help to ensure that glass is not broken during the installation process but the windows are generally supplied much longer to provide slimmer sightlines and there could be health and safety issues if the frames were supplied glazed due to the considerable weight of a glazed window.

Most windows and doors are now internally beaded using a “knock-in” glazing bead and the glazing process should become relatively easy once you have glazed a couple of apertures. Glazing packers are used to support and pack the glass so it is square in the aperture and the glazing bead is knocked into place using a rubber mallet. If you are glazing during cold weather it is a good idea to emerse the glazing bead in warm water which will help make the bead more flexible and easier to position. Your installation guide will detail the exact process used.

Finally, silicone sealant will need to be applied to all joints in accordance with your installation guide and the internal PVCu trims will need to be fitted to the roof eaves beam, ridge beam and glazing bars.

Your new self build conservatory should now be structurally complete and weather tight ready for the finishing internal touches.

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