Flush with best practice

Rehau’s Rio Flush Fit uses the company’s existing Total70 system profiles to make it easy to fit and forget. With that in mind, Clare Higgins, product manager at Rehau offers installers her best practice advice to ensure complete ease of install with a step-by-step installation guide.

Before we get into the nitty gritty of the install, it’s crucial that you have considered a few core elements up front. A full survey is always necessary and should be carried out by a competent person, while safe transportation should always be considered to ensure no products are damaged.

Likewise, storage of the window frame will ensure it is fully protected. Once you and the homeowner are happy with the plan and timeline, there are six key steps to follow that will ensure a smooth installation.

step one: removal of old frames

The Rio Flush Fit Window has been mooted as the market’s most realistic alternative to timber and aluminium windows – a key selling point for this style. Therefore, stage one of the process is arguably the most important as it is highly likely you will be removing previous timber or metal windows.

Timber removal. When removing timber frames, it’s easiest to remove opening lights first, complete with glass, by levering the screws from the frames, unscrewing the hinges or cutting through the hinges. Following this, any mullions and transom can be cut through to remove them from the outer frame of the windows. If original fixing nails or screws cannot be found and removed, the outer frame can be cut through twice to remove a small central piece of the outer frame. The frame can then be carefully levered from the surrounding aperture causing minimal damage.

Removal of metal windows. Depending on the type of window, there are a couple of ways in which metal windows can be removed. For example, if they are fixed through the frame into a timber sub-frame or direct into the aperture then you should remove all glazing from fixed lights, separate and remove all opening lights from the frames. Then you should locate the screws holding the metal frame in place and remove. Often, there will be timber sub-frame which will need removing as per above.

If the metal windows are set directly into the brickwork or concrete and held in place by lugs attached to the outer frame then there are additional stages to apply. Here you will require an angle grinder or hacksaw to remove any opening lights and then cut through any transoms and mullions to remove. It’s best to remove the screws from the frame by drilling out the heads or by driving them through the frame using a suitable punch.

Finally, cut through each side of the frame with an angle grinder and lever away from the wall taking care not to damage the fabric of the aperture.

If you are removing old plastic frames, box sash windows, or sub-sills, you can get further information on this via Rehau’s Installation Recommendations Guide which can be found on the Rehau Partner Portal.

step two: preparing the aperture

A short but vital stage in the process: it is crucial with any window install that you brush down the aperture and check the condition of the damp proof membrane (DPM). If it’s damaged, it must be replaced prior to install.

step three: position and prepare  

Positioning. When replacing any windows with the new Rio Flush Fit window, you should ensure it is positioned in the same position as the original frame. The new frame should bridge the DPM and the required expansion gap should be maintained, as well as being set back as far as possible within the aperture to shield it from the elements.

The joint between the element and the building must incorporate an adequate gap to ensure no damage will result from linear expansion, contraction or building distortion. We recommend a minimum of 5mm either side for white profile, or 10mm for coloured.

Preparation. When preparing the new Rio frame, special window fixings can be used in most situations and allow expansion movement. These are fixed to the frame with screws or by location between the frame lugs and should be firmly attached to the outer frame. Fixing to the building fabric is achieved with screws and wall plugs. Nails or shot rivets must not be used to fix frames. All anchoring materials must be protected against corrosion, be suitable for the building fabric and able to withstand the stresses transmitted.

step four: glazing up to standard

Whether you’re installing Rio or any other profile, all glazing should conform to the recommendations given in the relevant part of BS 6262 and in BS 8000-7. And while it may often be delivered to site ready-glazed, it can be supplied with glass units and pre-formed glazing beads to be applied on site in accordance with the manufacturer’s instructions. Again, this is a crucial step to ensure all insulating glass units are examined for damage prior to installation. They should then be installed in accordance with BS 8000-7.

step five: sealing into place

As we all know, a window that leaks air can also mean excessive energy loss and cost. With Rio being an ideal replacement window for more traditional (and potentially less efficient) properties, it is crucial that the sealing process is carried out precisely. The joint between elements and masonry must contain a foam sealing strip, polyethylene foam, or a similar material to act as a backing for the pointing mastic. If thermal or sound insulation is critical then the joint can be completely filled with mineral or sound insulation wool. If foam filling is to be applied to the areas between the elements and building fabric, windows should be attached by fixing bolts, not fixing brackets. Sealing mastic should be used to form the external seal and this must be compatible with the frame material.

step six: finishing off

Competing with premium materials such as timber and aluminium often means the Rio Flush Fit Window is being installed in affluent areas or high-spec buildings. Therefore, every attempt should be made during installation to ensure that debris such as wet plaster does not block drainage paths or impair operation of the hardware.

Internal reveals should be made good, ready for the customer to redecorate – a key feature of the Rio being that there is the option to match the interior of the home. On this point, when it is necessary to seal internally, sealants should be capable of accepting paint or wallpaper ie, not silicone. All internal sealant should be flushed off ensuring the frame and reveal are free of surplus sealant.

Once your Rio installation is complete, it’s important to fully inspect the windows alongside the homeowner to ensure they are 100% satisfied, as well as being familiar with the way in which they work.

While inspecting the windows, it’s also worth making sure there is a consistent seal gap between the sash and frame. If all is well, they should be given a Rehau Maintenance Tips Sheet to maintain the life of their windows.