Unless my hands are tied by the Building Dept. That doesn't necessarily make it correct nor the best way to build. Yet the inspectors insist of the same installation rules here in Florida as in Maine.Īnything may be tradition, accepted, and even legal or required. In recent years we are finally learning that many of the hard, fast rules about insulation do not work the same in all areas. But they seem to only know rules, and not reason. This continues to create exactly the same problems we have had for decades. This is due to the normal movement (movement, not settlement) all houses experience during climatic (temperature and humidity) changes.Įven here, we still have inspectors who have not kept up with the advancements in the industry, and continue to insist on nailing all the drywall tight in corners and intersections. A combination of Helifix Remedial products and traditional materials will be used to fix matters quickly, so that the tenant can complete his decorations.Click to expand.Actually, if you return to houses framed several years ago, you will often find cracks running not only along the wall-to-ceiling intersections, but also on the vertical wall corners. New diagonal binders will be screwed in and the cracks deeply raked, remedial wall ties installed and then re plastered over a mesh. The remedial work will involves securing the wall plates, checking and securing the truss feet to that and of course securing the lateral restraint at the apex. However, the bundle of defects suggests the roof has been flexing around on the wall plate and also putting thrust into both the eaves inner leaf and the gable apex. There is no single obvious cause of the problem. I surmise that the ties are few and far between or I would have expected the outer leaf to move out with the inner leaf, due to the compression of the ties. I check the cavity width and find it is slightly narrower where the inner leaf has moved out above the horizontal crack. I cannot locate ties in the upper part of the wall, but they could be there, hidden behind the insulation. I insert a boroscope into the eaves cavity but it is full of insulation. There are one or two fixings - rusty 'clout heads' half-halfheartedly placed, with a clear gap between the wood and the strap face - terrible. I wiggle them about, huffing and puffing indignantly (as surveyors do when they discover shoddy work). However, despite the correct placing in the wall, Most of them are not fixed to the trusses. On inspection I find that the straps are present. The building regulations apply here and the wall should have metal straps incorporated to allow this fixing. The rafters themselves also do this, even the diagonal posts do so. The truss bottom chords double as ceiling joists and, with the horizontal binders, they offer a secure fixing point. The restraint the wall needs is usually borrowed from the roof structure. This is significant because like all fluids, the air speeds up when it is passing through a small gap. The next house down the street is only 4m away. The wall will require additional support to resist wind loading. There are no purlins, with a trussed rafter arrangement. The apex of the gable has no copings on it and is merely dressed over with the roof tiles - a common detail. Would this cause the cracking? Not so sure at this point, but the omission speaks volumes about the site supervision, so maybe there are no straps at the eaves. Trusses will tend to slip sideways like dominoes if the horizontal and diagonal binders are absent. Well, when I say correct I see that the diagonal binders which should brace the trusses are loose, ill fitted and too short not extending from eaves to ridge. look further.Įntering the roof void the truss rafters are all present and correct. There could be some ties installed from above, perhaps the Helical type, which are stainless steel? These may be there but they do not show up on the metal detector and wouldn't anyway because the galvanised nail plates at the eaves joint of the truss bottom chord and the rafter, is too close and its spoiling things.Īt this point there is a suspicion that the roof has shifted a bit on the wall plate and that has transmitted thrust to the upper part of the inner leaf, causing rotation in section. I use a metal detector to scan the inner leaf along the eaves for evidence of the straps, which should hold the timber wall plates down to the blockwork - there are none. This is a late 90's semi so wall tie corrosion is out of the question. An external inspection reveals nothing, the external leaf is sound.
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