The Twisted Fix To Real Victorian Smokers………………………Answer To Mimi’s Question.

The Twisted Fix To Real Victorian Smokers………………………Answer To Mimi’s Question.

 

Victorian homes had multi-faceted high steep pitched roofs.

The Problem: This created downdraft problems for many of the chimneys. They would release smoke into the house and make house keeping cleaning a real chore.

One solution for this was to extend the height of the chimneys and this meant tall thin, usually freestanding, chimneys from the roof up to heights near to, if not exceeding the ridge of the roof.

This worked mostly, but the right (or wrong) weather conditions would cool these chimneys and cause thermal inversions and make them sometimes hard to light and also drafty. In some of these old homes most of the significant rooms had a fireplace.

Additionally they were subject to weather damage and were dangerous or more difficult to build (read costly). Being thinner (in general) they cooled more easily so they had condensation problems, which manifested itself as creosote buildup (increased risk of chimney fires) and more maintenance repairs.

The Fix: So architects and builders tried to incorporate the chimneys in the body of the roof as much as possible. The optimum plan allowed a chimney to rise to near the ridge and emerge with only the last few feet exposed to the elements. 

This worked very well, kept the chimney from excessive cooling, maintenance was relatively low and there were minimal draft problems. Great, but not all floor plans would allow this with straight chimneys. 

The Twist: Then the ‘offset flue’ construction of chimneys came about as a way to get the chimney to exit the roof as close to the optimal location as could be achieved. This was achieved by stepping off the successive layers of brick by small increments per layer.

Some referred to this a corbelling and structurally it is closer to cantilevering but here the weight of the masonry above counterbalances the overhang. As any toddler who’s played with blocks can tell you, there are limits as to how far you can go.

The physical realities limit how far the offsets can move the chimney and extended offsets also re-introduced draft problems as well. Fire regulations also limited the number of turns, lengths of runs and combinations of flues in a given chimney body.

So architects and the masonry trade soon learned to work within a well defined set of rules for successful application of this technique.

Look for gradual turns and smaller lateral displacements in proportion to the height rise.

If you have concerns consult with a specialist. ( A chimney sweep, a master mason, or a WETT certified technician. WETT = Wood Energy Transfer Technology.)

 

 

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This article was written by Robert Butler to answer a comment question from a previous article. ;

  Mimi’s QuestionI have a question.  I specialize in Victorian homes.  Many times in the attic the brick chimney stack is a little twisted between the attic floor and the exit at the roof line.  Any idea why they did that?  The first few times I thought it was the same drunken mason, but it is too consistent, and I have always wondered why.

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Original blog post on ActiveRain: Link to Blog Post

Do You Ever Have That Sinking Feeling?……………………….An OMG FIle.

 

Do You Ever Have That Sinking Feeling?……………………….An OMG FIle.

Do you ever feel like you are just floating along, not connected to any thing. Not grounded. Well you might not be if you are on a deck like the one shown below.

deck supports

You can see that the support beam that’s been added to this deck at mid-joist span to support and stiffen it. It is doing neither. It’s not even touching the joists or the footing post below itself.

It could be removed and it would have no effect on this deck. You’d never know it was gone.

Usually as support beam is larger than the joists it is supporting (or supposed to be supporting). This one IS a double thickness built up beam, but it’s 2/3s the size of the joists. The original joists and decking are pressure treated.

The footing of course is the floating type on the surface of the ground. That means it’s going wherever the frost takes it. So this deck will be having its ups and downs. A footing below frost depth is the only thing that is stable in this climate.

So you can see that nothing is touching here like it should be. You can also see there are no connectors. No nails, no screws, or no brackets.

Footings and foundations for buildings and structures, like decks, that are not anchored below the frost depth are described as floating footings.

In this case the structure might be more accurately described as flying rather than floating.

 

So when you buy a home you want to know you wont be sinking under repair bills. Get a full professional inspection.

 

 

 

Original blog post on ActiveRain: Link to Blog Post

“Faulty Towers”…..Funny, Faulty Decks………Dangerous !

“Faulty Towers”…..Funny,       Faulty Decks………Dangerous !

Faulty Towers was a hilarious British comedy. it was a sit-com staring one of the founding members of ‘Monty Pythons Flying Circus’.

Faulty decks though that’s a different kind of story, and if you are unlucky it’s appearing on a balcony or deck near you.

Take a look at the example below and remember just because it’s been there for a while doesn’t mean that it always will be (there).

deck defects

At ‘A” you can see the short remnant of the original cantilevered beam built into the original floor framing of this building.  The joists of the current construction are sistered onto either side. This is nailed with 4″ common nails, not galvanized.

B” Is the top end of the diagonal brace, a 4 by 4 bracketed by the sistered joists mentioned above. The same type of nails are used, but smaller ones.

C” the base of the same diagonal brace is set into a shallow pocket in the cement bonded stone foundation wall. There is a horizontal steel pin, basically a spike nail pining it from moving.

So whats wrong with that you say?

Well: Nails are just pins that lock things in place . The weight transfer has to be wood resting on wood.

Nailing wood the side of another wood member without notching it in to support it from underneath means the weight transfer is being done on the nails. Nails can not resist the stress over time.

They seem to work when everything is new and tight. Then things get a bit loose and flexible. For a while there is a little ‘wow’ deflection felt. It can last for years. You’ll even forget about it. “Oh, it’s OK, it’s aways been like that”.

The nails loosen from wood shrinkage, wood degrades from water exposure and nails rust, loose diameter and loose their hold strength.

Then one day it’s not OK. Gravity wins, you loose.

At ‘C‘ water collects here, keeping the wood wet, slowly rotting and the spike nail rusting.

To be safe:

A and B have to be bolted though with non rusting blots that pass through all the wood members and clamp them together. The number an spacing have to be staggered to prevent check splitting down the length of the grain.

C needs a rust proof bracket that holds the wood brace end off the stone to allow it to dry after rains and holds it securely on the stone foundation with through bolts. Lag bolting and cinch anchor bolts cannot be guaranteed to work on all kinds of stone.

Now look around the corner to this part of the structure:

ledger defects

Here we see some of the more common problems with decks.

The ledger board (against the wall), has no flashing and only has two (E) lag bolts set in mortar.

Now look at where the joists join onto the ledger (D). You can’t see the nails because they are very small. There’s only 5 of them and they are not galvanized.

To be safe; The ledger board has to be solidly attached. That means at least 5 bolts in this much space.

Ideally the bolts should be through bolts but if the stone is too friable then shorter lag or cinch anchor bolts can be used provided they are doweled into the stonework with epoxy. Of course they have to be galvanized or made of non-rusting alloys.

I’ve seen some amateur use of tapcons here (cement or masonry anchoring screws). They should never be used – they have even less shear strength than nails. They fail by just breaking off. The metal is not strong enough.

The ledger has to be flashed to keep it dry or wood rot decay will be a problem. Don’t count on pressure treated wood to be sufficient. Remember you are not building for the weekend or just the next ten years, you’re building for forever.

Lastly; Joist hangers – the proper type will not rust and each joist will be secured with 14 nails not not just 5 ‘toed’ nails.

DO NOT use screws at any structural joints including joist hangers or any other bracket that transfers weight. 

Fire code requires that all structural weight bearing or transferring joist brackets (and other similar hardware  attachments) be only attached with nails (not screws or ring shank nails).  This is for the safety of firemen so that when floors burn through, the joist and other horizontal timbers be allowed to release and fall without pulling down the walls on top of the firemen. Screws disrupt that release.

 

So if you’re looking at property anywhere in the Montreal area and you need a full inspection…………

 

Original blog post on ActiveRain: Link to Blog Post