How To Repair Broken Roof Joist

Structural Timber Repairs – Guide Covering How To Repair Structural Timbers Including Floor Joists, Roofing Joists, Joist Ends and Carrier Beams From Dry out Rot, Wet Rot and Woodworm Damage

Structural timber repair and treating joists confronting wet rot, dry rot and insect damage. This guide covers everything you need to know virtually repairing structural timbers including roofing joists and flooring joists when they take been damaged past wet rot, dry rot and insect attack such equally that from woodworm beetle. Nosotros show yous how to repair joist ends, carrier beams and wall plates with out the need to remove them.

Clammy and timber joists do non mix well. In fact damp and any kind of structural timber, exist it roof trusses, floor joists, doorframes, window frames and sills brand for (largely) ane or more than of iii types of existent damage.

Nosotros look closely at wet rot and its causes and effects, the lasting damage of dry out rot and how insect attack from woodworm and other wood boring beetles tin can severely compromise the structural (and other) timbers in the dwelling house.

If you need whatsoever help with whatever type of floor repair, structural timber repair, joist repair or timber treatment, Belongings Repair Systems expert staff will exist pleased to requite you completely complimentary, no obligation advice on 01626 872 650. The information you demand may exist in the project beneath. If non, telephone call them.

Damage to Timber Joists and Floors

There are three main types of timber damage, simply they are all caused by damp.

Timber will outset to decay at above 18% moisture content (in average softwood species, like an ordinary Pine), and so elimination of dampness is our chief business organization. 18% dampness means near one-fifth of the timber is clammy and this tin can happen purely as a upshot of condensation, leaking roofs, rising damp and other forms of exposure to moisture.

Timber in the home should exist inspected periodically to make sure it is non exposed to any of these bug.

Types of Damage to Structural Timber

Moisture Rot

When an surface area, or section is exposed to water, taking information technology'southward wet content above 18%, fungus or mycelium can beginning to "feed" off the timber and grow into and from the wood.

There are many types of fungus that make upwards the wet rot category, they include Coniophora Puteana and Poria Vaillantii with Coniophora existence the main culprit. The fungus feeds off the wood making it soft and spongy.

Wet rot is often showtime noticed when floors, especially ground-floor, flooring joists become springy under foot. Possible causes of moisture-rot are.

Unpainted and untreated timber exposed to water from roof
Condensation water arising from lack of ventilation to roof or floor timbers especially with hollow floors. Condensation tin can also badly effect window sills, when condensation wet is allowed to collect on window surfaces and run down and collect on a sills surface
Water accumulating and being soaked upward past timbers from leaking pipes, leaking wastes (bathroom or sink), hoses from washing machines and dishwashers etc…..
Rising damp making floor slabs and/or walls wet which in turn can bear upon the backs of skirting boards and door frames where no pigment is usually applied

For more data on identification of moisture rot, how it is acquired and the remedies for it, go to our project page.

Dry Rot

Starting in a moisture area of the timber, dry rot or Serpula Lacrymans is another fungus which literally sucks the life out of timber.

Different moisture rot nevertheless, when dry rot has consumed all the moisture from one damp surface area of timber, it searches out another and travels over all manner of surfaces to become to it. This manner it tin destroy whole properties if it'due south journey remains undetected.

The causes of the damp which attracts dry out rot can be the same as wet rot but the spores of the dry out rot fungus germinate and then spread in very fine, almost cob-web like strands. These strands tin travel across forest, plaster, brick and any surface where they tin get a hold in their search for new damp patches of timber.

Ways to identify dry out rot include:

Big mushroom blazon growths on the timber surface
Large, deep (mostly square shaped) cracks in the timber surface and cubing of timber
Orangish colour spots or spores around the mushrooms or any other growth appearing on the timber
Strings which look like a very dense cobweb running beyond surfaces.

For more information on dry rot, become to our information on dry rot identification, causes and remedies.

Insect Assail

Damp can concenter woodworm beetles such equally the Death Watch Beetle (Xestobium Rufovillosum) and woodboring Weevils (Pentarthrum Huttoni and Euophryum Confine) at the near extreme degree.

In fact, the woodboring weevil will by and large be institute in timber where fungus has started to take root. The causes of the damp can nonetheless exist the same simply the insect attack will exist fairly local. Most wood wearisome insects prefer timber with a fairly loftier moisture content.

Impairment from woodworm of any kind tin can originate either in the growing tree, where there is plenty of wet or in the timber yard where nigh timber planks are stacked, very shut to each other, allowing petty or no ventilation and the timber gets damp through both rain and condensation.

Signs of assail from woods boring insects or woodworm are usually the emergence holes (between 1mm and 1.5mm diameter). For more than information run across our project on woodworm and how to identify it.

Damaged timber joist caused by damp — Joist damaged by damp – Wet timber invites issues from fungi and insects

Damage to brick caused by damp — Damage to brick caused past dry rot soaking up wet as it travels across

Methods for Repairing Structural Timbers Safely

The ability to effect repairs on timber joists, beams, rafters, purlins, floorboards and all forms of structural timbers is not limited to today's techniques.

Carpenters have been splicing timbers with special joints for hundreds of years with many of these repairs nevertheless evident today in many old buildings and indeed, ships!

To brand the right selection for your repair yous may need some help over and higher up that offered on this folio. If so, then Property Repair Systems are at manus. Nosotros take worked with them for a number of years and can confirm their expertise in this field. Requite them a telephone call on 01626 872 650.

Firstly, look for the source of the trouble before you lot deal with the effects.

Equally good every bit modern methods are at repair and prevention of attack from water, moisture and wood tedious insects, information technology is tempting fate to just behave on with the repair until y'all have fairly diagnosed the cause of the problem.

If it is a clammy problem, look for (and repair) the source of the clammy.

You may need to re-roof or take a look at how your roof tiles are stock-still to your roof. It may be that they are not at the correct spacing (gauge) and the rain is blowing up underneath them.

It could also be that your chimney or other flashing's are not fitted correctly or take slipped out of their joints.

It could be that condensation is the crusade and has built up considering of lack of ventilation's. This can exist addressed on our pages dealing with the effects of condensation.

If leaking pipes or hoses are at mistake you demand to repair immediately to end further damage to the new piece of work you lot are about to do and if the damp problem has arisen because of a faulty damp proof course then this needs to be addressed urgently.

Repairing Joist Ends

The supported ends of joists tin become damp because they rest within or shut to the support walls and hands absorb water from damp soil, humid air or water leaks.

This can include h2o traveling over the acme of the brickwork through loose or broken tiles and blocked gutters. Wall plates can be affected also.

If there is little or no ventilation in the clammy area, the wet will not take the chance to evaporate and the timber will develop fungus as explained above therefore whatever repair or handling must include attention to the Air Bricks or other ventilation (Come across our project roofing air bricks and vents).

There are a number of means to repair structural timber. The easiest way to repair joist ends is to fit joist repair plates.

These come equally a pair of ″L″ shaped, metal plates complete with screws and instructions.

They accept the advantage that joists are extended dorsum into or onto the original bearing.

Repairing joists using joist repair plates — Joist repair plates are bolted to the sides of damaged joists

Joist repair plates fixed to timbers — Joist repair plates stock-still to timbers

How to Position, Fix and Align Joist Plates

The all-time way to repair the end of a joist is to remove the damp or affected stop after the flooring or ceiling has been propped upward equally one would if removing or forming an opening through a load-bearing wall, with Acrow Props.

A new piece of timber is cut (A) to supplant the damaged piece and the joists plates are positioned ether side of the joists with the end of the joist plate correct up confronting the edge of the timber so information technology is the joist plate that site on the bearer (A).

The joist plate is bolted to the timber making the joint (B) equally strong equally the original joist. The length of the joist plate on the original side of the joist (C) is usually at least twice that of the piece that replaces the damaged department (A).

Treating Joist Ends

As well as a joist plate, if required, the end grain cutting (A) and the back up area should be thoroughly treated with Boron Ultra Gel and a slice of damp proofing material, such as DPC plastic should then be placed underneath, to prevent damp from finding its way from the wall into your new timber. Use pre-treated timber if possible.

The Boron Gel is diluted with h2o to create a v% solution and painted on the ends, and joints of timber. This and then provides a barrier to prevent assault from woodworm and too will fend off dry rot.

Boron Gel prevents damp and insect attack — Applying Boron gel past brush to new or damaged timber

Providing Enough Air Flow to Prevent Damp

Most properties volition characteristic air bricks – these allow the flow of air either in roof spaces or under suspended floors and prevent the build-up clammy and moisture. When it comes to air bricks on the outside wall of your property you lot should ensure that there is at least i brick per 2.25 meters of outside wall length.

You volition besides accept to ensure that whatever outside ground is significantly below any air bricks equally if not, this may restrict air flow and damp issues may event.

To these ends, ensure that air bricks are articulate from soil build-up, pathways or tarmac and other obstructions.

Repairing Carrier Beams and Support Beams

Carrier or support beams are usually larger timbers than joists and in respect to this, it might not be possible to apply the joist repair plate organisation previously mentioned.

Carrier and support beams are usually (these days) installed as steel RSJ'southward but in older properties or barn conversions these may well be existing timbers or indeed new, very large timbers, to maintain the integrity of the edifice and also to maintain it's traditional aesthetic look. There may also be certain conservation rules that stipulate that any repairs should maintain an existing wait.

If timbers are larger than x 10 two inches (or 250mm 10 50mm) then the most suitable repair volition be to utilise a Timber-Resin Splice.

This organization ordinarily comes in the form of a kit for like shooting fish in a barrel use and provides a new slice of timber (D), with zinc plated high tensile metallic bars or rods (E).

Resin bonded high tensile steel rods — Using resin bonded confined to repair joists and rafters

These high tensile confined volition be pre-bonded into one end of the timber beam, ready for you to fit using the resins provided in the kit.

The basis of this repair method involves firstly supporting the timber so that the load weight is taken off the supporting point and the weight from the to a higher place flooring or roof is stable then the damaged department of timber is cut off far enough along the length of the timber then that only undamaged timber is left. Obviously now your timber is going to exist besides short to reach the original support.

To resolve this, in the length of timber that is left you will now need to cutting a slot in the height of it that is slightly longer than the protruding high tensile bars in the replacement timber splice you take. At present y'all can place your timber splice upwardly to the existing timber with the high tensile bars resting in the slot that y'all have simply cut.

Slot cut in existing timber to take steel rods in timber splice

Finally, the resin supplied with the kit is poured into the slot, bonding the high tensile bars into the existing timber. Once the resin has cured and set, the supports tin can exist removed and the new splice section will so rest on the original supporting point creating your newly repaired timber.

If yous would like some more information on the process of using joist splice kits to extend the joist to the wall plate and mount it back in position have a wait here.

Treating Carrier Beams and Wall Plates

Boron is an excellent handling for damp timber. It can be applied equally a paste and inserted into 10mm holes drilled in the timber.

The properties of Boron volition kill all wood tedious insects as well as killing and preventing further growth of all fungicidal spores which are the causes of wet and dry out rot.

The image below shows boron paste existence injected in to a 10mm hole drilled in a new piece of timber which is almost to be attached past joist plates, to an existing roof timber.

Filling pre drilled holes with Boron paste — Boron paste as used in timber joists and rafters

A surface applied Boron Gel can also be used equally can the paste and solutions mentioned above. Manufacturers advice (FREE) from Property Repair systems should exist sought on 01626 872 650 before deciding which method to employ for repairing and preventing farther damage of your roof or floor timbers.

All projection content written and produced past , founder of DIY Doctor and manufacture good in building technology.